Editor's Note: Standard, internationally preferred terms and definitions are highlighted in blue. Terms and definitions in black are acceptable, but only if the standard internationally preferred terms and definitions are unacceptable for a certain context. Terms highlighted in red are not acceptable in the international standards community. They appear for educational purposes only. Notes and examples included with definitions are illustrative, and are not to be considered part of the standard definition.

Terms and definitions are often derived from international standards (eg, International Organization for Standardization [ISO] documents). In order to align terms in the Harmonized Terminology Database with their source material, and to ensure that users of the database select the most current terms available, terms may be updated before revision of the CLSI documents in which they appear. This practice does not compromise the utility of the existing CLSI document. For questions regarding this policy, please e-mail standard@clsi.org.

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22q11.2 deletion syndrome

a highly variable clinical syndrome caused by a contiguous deletion of 1.5 to 3 Mb in the long arm of one copy of chromosome 22

Project: NBS06

NOTE 1: The clinical manifestations of 22q11.2 deletion syndrome can include, but are not limited to, congenital abnormalities of the heart, thymus (leading to T-cell immunodeficiencies), palate, parathyroid and thyroid glands, learning disabilities, speech and developmental delay, and psychiatric problems; NOTE 2: The phenotype is variable and does not correlate with the size of the deletion; NOTE 3: Approximately 93% of cases are caused by a de novo deletion, and approximately 7% are inherited from a parent in an autosomal dominant manner; NOTE 4: DiGeorge syndrome, velocardiofacial syndrome, and conotruncal facial anomaly refer to clinical syndromes in which the majority of patients have been found to have a 22q11.2 deletion.


3´ poly(A) tail

a sequence of adenylyl residues at the 3´ end of eukaryotic mRNA

Project: MM13

NOTE: Almost all mature eukaryotic mRNAs have 3´ poly(A) tails of 40 to 200 nucleotides, those of histones being a notable exception. The poly(A) tail is added enzymatically to the primary transcript, which is first cleaved 10 to 30 nucleotides past a highly conserved AAUAAA sequence. The poly(A) tail is then generated from ATP through the activity of polynucleotide adenylyltransferase. In practical terms, the poly(A) tail on mRNA has facilitated its ready isolation from total cellular RNA by affinity chromatography on oligo(dT) cellulose.


3-amino-9-ethylcarbazole

a soluble substrate for horseradish peroxidase that generates a colored, insoluble product

Project: I/LA26

NOTE: It is often used in enzyme-linked immunospot assays, as well as Western blots.


3-parameter display

a graphic representation of data in which correlated values for three different parameters measured on the same cell are plotted.

Project: H43


5´ cap

a structural feature present at the 5´ end of most eukaryotic (cellular or viral) mRNA molecules and also some virion mRNA molecules, but not of bacterial mRNA molecules;

Project: MM13

NOTE: It consists of a residue of 7-methylguanosine (m7G cap) and a triphosphate bridge linking it 5´-5´ to the end of the polynucleotide chain. The cap structure is thought to protect the 5´ end of the mRNA from degradation by phosphatases or nucleases and to facilitate initiation of translation of mRNA by the eukaryotic (but not the bacterial) ribosome.


5´ nuclease assay

a method using a quenched fluorescently labeled probe that anneals to one strand of the polymerase chain reaction (PCR) amplicon that is, in turn, cleaved during the extension phase of the PCR by the 5′ to 3′ exonuclease activity of many thermostable DNA polymerases;

Project: MM03

NOTE: The cleavage releases a fluorescent label from the 5′ end of such a probe. After many cycles, the level of fluorescence increases until it exceeds a background threshold and can be measured by a variety of instrumentation.


5´ untranslated region

a particular section of messenger RNA and the DNA that codes for it. It starts at the +1 position (where transcription begins) and ends just before the start codon (usually AUG) of the coding region. It usually contains a ribosome binding site.

Project: MM19


abnormal reference range

a range of percentage of cells with an expected abnormal pattern among patients with a known clinical entity.


abnormality

1) an abnormal condition, state, or quality; irregularity; deviation (RHUD1.7CD); 2) In Hematology, a clinically significant alteration in the distribution of mature cell types, or the presence of immature or abnormal cell types at or above clinically significant levels or fractions.

Project: NRSCL8, H20


abnormality

a clinically significant alteration in the distribution of mature cell types, or the presence of immature or abnormal cell types at or above clinically significant levels or fractions

Project: NRSCL8


absence of heterozygosity

general term to describe the observation of an interval lacking heterozygosity. This observation may represent constitutional homozygosity (regions identical by descent or secondary to uniparental disomy) or a somatic mechanism (eg, deletion, mitotic recombination).

Project: MM21


absolute count

a term used in hematology and molecular biology for the number of cells or sequence copies per unit volume of sample;

Project: NBS06

NOTE: The term “absolute” refers to the distinction from “relative count” and does not imply any specific level of standardization.


absolute FTH measurement procedures

rely on standard hormone solutions in buffer as calibrant, whose concentrations have been established gravimetrically or by other similar analytical means

Project: C45

NOTE: Dialysis and UF measurement procedures (whether direct or indirect) typically fall into this category, since such calibrants are normally used either to measure the FTH concentration in the dialysate in the first case, or the total concentration in the sample in the second case.


absorb

to take up or receive by chemical action; to take in and utilize (RHUD1.7CD).

Project: NRSCL8


absorb

to remove one reactant by the addition of another soluble reactant (neutralization), as the activity of an antibody may be neutralized by the addition of soluble antigen. See also adsorb


absorbance

(A) in optics, the capacity of a substance to absorb radiation; NOTE: Expressed as the logarithm of the reciprocal of the transmittance of the substance; A = log (1/T) = -log (T).


absorbance

(A) 1) in optics, the capacity of a substance to absorb radiation; 2) decadic absorbance – the negative decadic logarithm of one minus the absorptance

Project: VET03, VET04

NOTE 1: Absorbance is expressed as the logarithm of the reciprocal of the transmittance of the substance; A = log (1/T) = -log (T); NOTE 2 Formerly, the term "optical density" was used. The use of this term is discouraged.


absorbance

(A) the logarithm of the ratio of radiant power (Io) incident on the sample to the radiant power (I) transmitted by the sample; A = log IoI

Project: H15, I/LA29

NOTE 1: Alternative terms sometimes used are "extinction" and "optical density"; NOTE 2: The wavelength at which the absorbance is measured can be shown as a superscript, the component of which the absorbance is measured as subscript, e.g., A540HiCN = absorbance of hemiglobincyanide at 540 nm


absorptance

the radiant power absorbed by a system;

Project: NRSCL8

NOTE: The power absorbed divided by incident radiant power; a = f abs / f0.


absorption

a taking in or reception by physicochemical action.

Project: NRSCL8


absorption

a process by which a substance is taken up in bulk by a material (absorbent) and held in pores or interstices in the interior; See also adsorption.

Project: NRSCL8


absorption

a process by which a substance is taken up chemically or physically in bulk by a material (absorbent) and held in pores or interstices in the interior;

Project: GP40

NOTE: See also adsorption, sorption.


absorption

the removal or neutralization of antigen and/or antibody from a solution by the addition of the other soluble reactant, i.e., the antibody and/or antigen.


absorption

the removal of energy or particles from a beam by the medium through which the beam propagates.


absorption

uptake of substances by a tissue, as of nutrients through the wall of the intestine.


absorptivity

(absorption coefficient) a measure of the absorption of radiant energy (P) having a given wavelength and/or frequency as it passes through a material of substance concentration of one mol/L; P = Po · e- eb, where Po is the power of the incident light and b is the optical path length.

Project: NRSCL8


absorptivity

(molar extinction coefficient) a measure of the absorption of radiant energy having a given wavelength and/or frequency as it passes through a material of substance concentration of one mol/L.

Project: I/LA24


absorptivity

a measure of the absorption of radiant energy having a given wavelength and/or frequency as it passes through a material of substance concentration of one mol/L.

Project: I/LA24


accelerated stability testing

a stability study designed to increase the rate of chemical or physical degradation of an IVD reagent by using exaggerated environmental conditions (eg, light, temperature, humidity);

Project: EP25

NOTE: Results from such studies may be used to compare the influence of product design/packaging factors or, in some cases, to estimate the expiration date when the product is handled under recommended storage conditions.


acceptability

based on individual criteria that set the minimum operational characteristics for a measurement procedure.

Project: EP10, C62


acceptable risk

a state achieved in a measuring system where all known potential events have a degree of likelihood for or a level of severity of an adverse outcome small enough such that, when balanced against all known benefits—perceived or real—patients, physicians, institutions, and society are willing to risk the consequences

Project: GP47, EP23


acceptance criteria

a defined set of conditions that must be met to establish the performance of a system;

Project: MM21, AUTO13

NOTE: These conditions define the acceptability of the software from the user’s perspective.


accepted reference value

a value that serves as an agreed-upon reference for comparison, and which is derived as a) a theoretical or established value, based on scientific principles; b) an assigned or certified value, based on experimental work of some national or international organization; c) a consensus or certified value, based on collaborative experimental work under the auspices of a scientific or engineering group; or, when a), b), and c) are not available, the expectation of the (measurable) quantity, ie, the mean of a specified population of measurements (ISO 5725-1)

Project: QMS24, EP17, EP10


accepted reference value

a value that is traceable to a standard of highest metrological order (eg, isotope dilution-gas chromatography/mass spectrometry) that serves as an agreed-upon reference for comparison and which is derived as a theoretical or established value based on scientific principles; an assigned value based on experimental work of some national or international organization; or a consensus value based on collaborative experimental work under the auspices of a scientific or engineering group (modified from ISO 5725-1)

Project: POCT13


access control

protection of system resources against unauthorized access; a process by which use of system resources is regulated according to a security policy and is permitted by only authorized entities (users, programs, processes, or other systems) according to that policy. (RFC 2828)

Project: AUTO09


access point

a function or step in the operation of software that allows the “inputting” of information;

Project: AUTO13

NOTE: An access point can influence the behavior of the system.


access point

(AP) a piece of equipment that connects and merges data from one or more point-of-care testing devices into an interface or communication link to a network;

Project: POCT02

NOTE: Examples of access points include single- or multiple-port connection equipment, typically connected to a network (a local area network [LAN]); or an access point can be part of more complex equipment, such as bedside patient monitors or personal desktop computers.


access point

(AP) a subsystem that consolidates data from one or more point-of-care devices (POCD) onto another communication link;

Project: POCT01

NOTE: Examples of access points include a multiport concentrator or a dedicated single-port access point, typically connected to a local area network (LAN), or an access point that is part of a multifunctional device such as a patient monitor or personal computer.


access point interface

(API) specifies the interface (principally input) to an access point or concentrator;

Project: POCT01

NOTE: This definition is equivalent to IEEE ‘BCC.’


accession

the steps required to ensure that a specific patient specimen and the accompanying documentation are unmistakably identified as referring to the same patient.


accessory

article intended explicitly by its manufacturer to be used together with an IVD medical device

to enable the IVD medical device to achieve its intended purpose or to augment or

extend the capabilities of the IVD medical device in the fulfilment of its intended purpose (ISO 18113-1)

Project: ISO 18113-1

NOTE: Adapted from §5.0, NOTE 3 of Global Harmonization Task Force (GHTF), Information Document 1206 Concerning the Definition of the 1207 Term ‘Medical Device,’ Final Document GHTF/SG1/N29R16:2005, May 20, 2005.


accident

an undesirable or unfortunate happening that occurs unintentionally.

Project: QMS11, QMS01


accompanying document

document accompanying a medical device and containing information for those accountable for the installation, use, and maintenance of the medical device, the operator, or the user, particularly regarding safety (ISO 14971)

Project: ISO 14971


accreditation

third-party attestation related to a conformity assessment body conveying formal demon­stration of its competence to carry out specific conformity assessment tasks (ISO/IEC 17000)


accreditation

process by which a private, peer-level commission or association evaluates and ensures that a program of professional study or activity, such as laboratory testing, in an institution is meeting appropriate standards of organizational performance.

Project: POCT10


accreditation

process by which an authoritative organization gives formal recognition that a laboratory is competent to carry out specific tasks (modified from ISO 15189)

Project: QMS21, QMS25, QMS17, QMS01, MM19, QMS05, QMS14, QMS15, MM22, QMS20


accreditation body

authoritative body that provides third-party attestation that a laboratory fulfills specified requirements and is competent to perform specific tasks;

NOTE: The authority of an accreditation body is typically derived from government.


accreditation organization

authoritative organization that provides attestation that a laboratory is competent to carry out specific analytical activities

Project: QMS24


accrediting agencies

organizations that certify and/or monitor the quality activities of clinical laboratories (eg, the College of American Pathologists, The Joint Commission, World Health Organization, and the South African National Accreditation System).

Project: MM14


accuracy

(of measurement) closeness of agreement between a measured quantity value and a true quantity value of a measurand (JCGM 200:2012)

Project: M52, MM21, POCT14, H48, POCT04, QMS24, C24, ISO IEC Guide 99, H58, GP16, POCT05, M44, I/LA20, C34, EP18, M55, POCT09, C43, GP44, M51, EP30, H26, NBS04, MM06, M24, I/LA28, GP34, H02, I/LA34, EP23, C58, MM19, NBS05, EP29, M11, MM05, MM01, C56, EP31, EP27, MM20, MM14, EP09, EP26, C40, MM22, MM09, H60, EP14, C62, C57, MM03, MM23, POCT06, EP19

NOTE 1: The concept "measurement accuracy" is not a quantity and is not given a numerical quantity value. A measurement is said to be more accurate when it offers a smaller measurement error (JCGM 200:2012); NOTE 2: The term "measurement accuracy" should not be used for "measurement trueness" and the term "measurement precision" should not be used for "measurement accuracy," which, however, is related to both these concepts (JCGM 200:2012); NOTE 3: "Measurement accuracy" is sometimes understood as closeness of agreement between measured quantity values that are being attributed to the measurand (JCGM 200:2012); NOTE 4: “Accepted reference value” may be used in place of “true value”; NOTE 5: “Measurement accuracy” is inversely related to “measurement error” and “measurement uncertainty,” and directly related to “measurement precision"; NOTE 6: For nucleic acid sequence analysis, the overall accuracy refers to the closeness of the derived assembled sequence to the true sequence; NOTE 7: Because M52 is a US-focused document, the term “analyte” is used instead of “measurand” throughout the document; NOTE 8: In microbiology, the ability of a microbial identification system to correctly identify the organism being tested; NOTE 9: For antimicrobial susceptibility testing, the agreement of the AST system result with the result generated for the same isolate with the appropriate reference method; NOTE 10: In the case of total serum immunoglobulin E (IgE) assays, the US IgE Standard  and the international IgE standard (11/234 are available for use as primary reference materials to promote trueness;NOTE 11: For IgE antibody assays of defined allergen specificity, there are currently no universally accepted IgE antibody standards with calibrated levels of allergen-specific IgE. Heterologous interpolation of allergen-specific IgE antibody results from a total IgE dose response curve has become a universally accepted calibration method. Over the years, several research-based secondary IgE antibody standards have been prepared with mass per volume unit estimates using antibody adsorption or depletion methods.


accuracy

(of measurement) closeness of agreement between a single test result and the accepted reference value (modified from ISO 5725-1)

Project: POCT17, POCT13, C48


accuracy

(of measurement) closeness of agreement between a measurement result and the accepted reference value (ISO 17593)

Project: ISO 17593

NOTE 1: The term "measurement accuracy," when applied to a ser of test results, involves a combination of random components and a common systematic error or bias component (ISO 17593); NOTE 2: For oral-anticoagulation monitoring systems, accuracy is measured by the extent to which measurements of blood samples from different patients agree with INR values traceable to a thromboplastin International Reference Preparation (IRP).


accuracy

(of measurement) closeness of agreement between a measured quantity value and a true quantity value of a measurand (JCGM 200:2012)

Project: C52

NOTE 1: In drug testing, accuracy also refers to a test’s ability to detect a measurand when it is present at a concentration equal to or above a specified cutoff value; NOTE 2: Due to their inherent limitations, immunoassays are expected to produce some false-positive and false-negative screening results, thus definitive testing is warranted.


accuracy

(clinical or diagnostic) the qualitative or quantitative expression of a particular WBC differential finding in terms of sensitivity, specificity, efficiency, positive predictive value, and negative predictive value;

Project: H20

NOTE: It is the separate predictive value statements that are medically meaningful.


accuracy

the ability of a microbial identification system to correctly identify the organism being tested.

Project: M50


accuracy

(of measurement) closeness of agreement between the result of a (single) measurement and a true value of the measurand (analyte) (modified from ISO 17511)

Project: I/LA21, POCT10

NOTE: Accuracy is not a synonym for trueness, but is the combination of trueness and precision (modified from ISO 3534-2).


accuracy

the closeness of agreement between a test result and the accepted reference value (ISO 5725-1)

Project: EP21, MM17, C44, C37, H44, ISO 15198, GP40, AUTO08, EP17

NOTE 1: The term "accuracy," when applied to a set of test results, involves a combination of random components (imprecision) and a common systematic error or bias component (modified from ISO 5725-1); NOTE 2: For oral anticoagulation monitoring systems, accuracy is measured by the extent to which measurements of blood samples from different patients agree with INR values traceable to an International Reference Preparation (IRP) (ISO 17593).


accuracy

closeness of agreement between a measured quantity value and the true value of the quantity intended to be measured (modified from JCGM 200:2012).

Project: I/LA26


accuracy

(of process measurement) closeness of the agreement between the result of a measurement and the true dynamics of the measurand;

Project: POCT05

NOTE: Temporal accuracy is the combination of point and trend accuracy.


accuracy

1) how close a test result for a specific analyte is to how much of the analyte is there; 2) the closeness of agreement between a test result and the accepted reference value (ISO 5725-1)

Project: POCT08


accuracy class

class of measuring instruments or measuring systems that meet stated metrological requirements that are intended to keep measurement errors or instrumental measurement uncertainties within specified limits under specified operating conditions (JCGM 200:2012);

Project: JCGM 200:2012

NOTE 1: An accuracy class is usually denoted by a number or symbol adopted by convention (JCGM 200:2012); NOTE 2: Accuracy class applies to material measures (JCGM 200:2012).


acid α-glucosidase

(GAA) a lysosomal enzyme, encoded by the GAA gene that hydrolyzes terminal, nonreducing (1,4 and 1,6)-linked α-D-glucose residues with release of α-D-glucose

Project: NBS07

NOTE 1: Also known as acid maltase; NOTE 2: Pompe disease is caused by a deficiency of this enzyme.


acids

chemicals with a pH lower than 7

Project: QMS04

NOTE: Acids can cause serious burns on human skin and many other materials.


ACK

1) a data field name for a general acknowledgement message as specified in the HL7 protocol (HL7 V2.6); 2) a communication control character transmitted by a receiver as an affirmative response to a sender (ASTM).

Project: AUTO01, AUTO02, AUTO03


acoustics

the study of sound;

NOTE: This is used in determination of the sound absorbance and transmission properties of various materials used in a construction project.


acquisition method

method of analysis for the mass spectrometer to acquire data

Project: NBS04, NBS04

NOTE: Three data acquisition methods are used in newborn screening: precursor ion scanning, selected reaction monitoring (SRM), and neutral loss scanning.


acridinium ester

compound that undergoes a light emitting reaction in the presence of a dilute aqueous solution of sodium hydroxide and hydrogen peroxide; the amount of compound can be quantified by measurement of the intensity of the emitted light or rate of photon emission;

Project: MM17

NOTE: The compound reacts with other substances containing primary and secondary aliphatic amines to yield chemiluminescent derivatives.


actin

see beta-actin (ACTB) gene.

Project: NBS06


action personnel

the personnel responsible for and having the authority and resources to lead or coordinate the implementation of a plan.


activated carbon

porous carbon material used for removal of impurities

Project: GP40

NOTE: See Section 6.5 of CLSI document GP40 for details.


activated clotting time

(ACT) a global coagulation test which is particularly sensitive to abnormalities in the intrinsic blood coagulation pathway and the anticoagulant activity of heparin;

Project: POCT14

NOTE: The ACT is a measurement of the time in seconds required for a clot to form in a native (i.e., nonanticoagulated) blood specimen that has been exposed to a contact activator of the intrinsic phase blood coagulation pathway.


activated partial thromboplastin time

the time, in seconds, required for a fibrin clot to form in a plasma sample after appropriate amounts of calcium chloride, and a partial thromboplastin reagent (phospholipid plus a contact activator), are mixed with the sample

Project: H21, H57

NOTE: The activated partial thromboplastin time measures the intrinsic and common coagulation pathways.


activated partial thromboplastin time (point-of-care)

The activated partial thromboplastin time performed using a point-of-care (POC) test system.


activated partial thromboplastin time test

A global coagulation test used for the evaluation of the intrinsic and common coagulation pathway and for monitoring therapy with unfractionated heparin and certain other anticoagulants;

Project: POCT14

NOTE: The APTT is the time in seconds required for a fibrin clot to form in a plasma sample after an optimal amount of calcium chloride, a partial thromboplastin  reagent (phospholipid), and contact factor activating agent have been added to the sample.


activation

when referring to platelets, a series of processes and events that change a discoid platelet into a spiny, spiculated entity with extension of pseudopodia that results in the initiation of signal transduction.

Project: H58


active error

error by a front-line operator (ISO/TS 22367)

Project: ISO/TS 22367


active ingredient

constituent that participates in the reaction used to measure or detect the analyte


active ingredient

a component that is included in a chemical reagent or medium that has a pharmacological effect on microorganisms (eg, inhibitor, nutrient, preservative, or stabilizer).

Project: M40


active safety device

a device requiring a user to take action to actively engage the safety feature to ensure its proper function.

Project: X03


activity

the capacity of a substance to react, corrected for the loss of reactivity due to the interaction of its constituents.


activity concentration

of a radioactive material, the activity of the contained radionuclide to the volume of material.

Project: NRSCL8


activity of a radioactive material

the number of radioactive transitions taking place in a sample per unit time.

Project: I/LA23


acute HIV infection

the phase of infection that occurs between the time of first detection of HIV by virological assay (eg, RNA, DNA, or viral antigens) until the first detection of confirmed HIV-specific antibodies.

Project: M53


acute phase reaction

the physiological response to inflammation, injury, illness, or stress, in which a variety of plasma proteins become increased in concentration, or, in the case of some proteins, decreased in concentration;

Project: H60

NOTE: A subset of these proteins affects coagulation, eg, factor VIII, fibrinogen, and von Willebrand factor become elevated.


acylcarnitine

carnitine esters that are derived by conjugation of fatty acids and carnitine through the alcohol group and function as biomarkers for a number of inherited metabolic disorders (fatty acid oxidation disorders and organic acidemias)

Project: NBS04

NOTE 1: The fatty acid attached to carnitine reflects the composition of fatty acids within the mitochondria and is typically between two and 20 carbons, may be saturated or unsaturated, and may contain a hydroxyl or carboxylic acid group; NOTE 2: The elemental composition of the fatty acid is important in determining the mass of the acylcarnitine and, hence, its identification. NOTE 3: Throughout this guideline, the acylcarnitine species are referred to by their acyl chain carbon lengths (eg, octanoylcarnitine is referred to as “C8”); NOTE 4: See carnitine.


adapter

(oligonucleotide adapter) a short sequence of deoxynucleotides used to couple segments of oligonucleotide.

Project: MM09


addendum

request for information adding to or clarifying the construction bidding documents

Project: QMS04

NOTE: These are generally issued during the bidding phase as part of the construction contract documents.


additional service

services of the architects and/or engineers that may be required for the project but were not originally specified in the contract

NOTE: These would only be done with authorization from the owner.


additive

in a specimen collection tube, any ingredient that is placed in a collection container to facilitate an intended function (eg, to prevent the blood from clotting or to prevent glycolysis);

Project: GP39, POL1/2, GP34

NOTE: Although the container closure is not considered an additive, it may contain or be coated with additives, which, if they come into contact with the specimen, may be considered additives.


adhesion

the process by which platelets attach to surfaces or surface-bound proteins by certain glycoproteins, selectins, and integrins.

Project: H58


adjusted variance

a statistical manipulation that adjusts the measured variance by subtracting components from other sources of variance;

Project: EP10

NOTE 1: For example, between-run variance is adjusted by subtracting the contribution from within-run variance; NOTE 2: Appendix C of CLSI document EP10 describes a measurement procedure for determining adjusted variance.


adjustment

(of a measuring system) set of operations carried out on a measuring system so that it provides prescribed indications corresponding to given values of a quantity to be measured (JCGM 200:2012);

Project: JCGM 200:2012

NOTE 1: Types of adjustment of a measuring system include zero adjustment of a measuring system, offset adjustment, and span adjustment (sometimes called gain adjustment) (JCGM 200:2012); NOTE 2: Adjustment of a measuring system should not be confused with calibration, which is a prerequisite for adjustment (JCGM 200:2012); NOTE 3: After an adjustment of a measuring system, the measuring system must usually be recalibrated (JCGM 200:2012).


adjuvant

a substance admixed with an immunogen to elicit a more marked immune response (RHUD1.7CD).

Project: DI01, I/LA23


administrative controls

the implementation of management policies, work practices, and written procedures designed to reduce exposure of personnel to hazards (eg, written safety rules, safety training and competency assessment, specific work practices in procedure documents).

Project: M29


admission screening

a screening specimen collected on admission or within a short time after admission before the onset of other treatments and interventions.

Project: NBS03


adsorb

to gather a gas, liquid, or dissolved substance on a surface in a condensed {usually monomolecular}layer (RHUD1.7CD);

NOTE: Materials such as plastic, glass, or particles (latex, bentonite, cellulose, etc.) are used for the removal of antibodies or antigens by immobilizing the appropriate reactant to the surface (Cf. DI1, C3). Contrast with absorb.


adsorption

a process by which a substance is bound at the surface of a material (adsorbent). See also absorption.

Project: NRSCL8


adsorption

adherence of molecules, atoms, and ionized species of gas or liquid to the surface of another substance (solid or liquid) as the result of a variety of weak attractions that involve ionic, Van der Waals, and surface-active (hydrophobic/hydrophilic) forces;

Project: GP40

NOTE: See also absorption, sorption.


ADT

1) an abbreviation for admission, discharge, or transfer; 2) a data field in a hospital information system denoting admission, discharge, or transfer.

Project: AUTO01, AUTO02, AUTO03


adulterant

urine drug donors may add a substance (adulterant) to their specimens that will cause it to test negative on initial screening (adulteration);

Project: C52

NOTE: Use of adulterants to avoid detection in forensic testing is considered to be even more serious than drug abuse itself.


Advanced Encryption Standard

(AES) a future Federal Information Processing Standards (FIPS) publication being developed by NIST to succeed the Data Encryption Standard (DES). It is intended to specify an unclassified, publicly disclosed, symmetric encryption algorithm, available royalty-free worldwide (RFC 2828).

Project: AUTO09


adventitious agent

a contaminating agent–including bacteria, fungi, mycoplasma, endogenous and exogenous viruses–present in the inoculum or the substrate and/or materials used in the production of a biological product.


adverse event

term for any event that is not consistent with the desired, normal, or usual operation of the organization.

Project: QMS11


adverse event

untoward incident, therapeutic misadventure, iatrogenic injury, or other adverse occurrence directly associated with care or services provided within the jurisdiction of a medical center, outpatient clinic, or other health care facility;

Project: POCT12

NOTE: Adverse events may result from acts of commission or omission (eg, administration of the wrong medication, failure to make a timely diagnosis or institute the appropriate therapeutic intervention, adverse reactions or negative outcomes of treatment) (see US Department of Veterans Affairs.)


advisory notice

communication issued by an organization, subsequent to delivery of a medical device, to provide supplementary information and/or to advise what action should be taken in
⎯ the use of a medical device
⎯ the modification of a medical device
⎯ the return of a medical device to its manufacturer
⎯ the destruction of a medical device (ISO 18113-1)

Project: ISO 18113-1

NOTE: Issue of an advisory notice might be required to comply with national or regional regulations (ISO 18113-1). 


aerosol

a system of respirable particles dispersed in a dust, gas, smoke, vapor, or fog that can be retained in the lungs (modified from ISO 15190)

Project: M29

NOTE 1: Aerosol particles generally are ≤ 5 µm in size; NOTE 2: See droplet nuclei.


aerosols

system of particles dispersed in a gas, smoke, or fog (ISO 15190)

Project: POL1/2, ISO 15190


aerosols

system of respirable particles dispersed in a dust, gas, smoke, vapor, or fog that can be retained in the lungs (modified from ISO 15190)

Project: QMS04

NOTE: Aerosol particles range in size from 1 to 5 µm.


aerotolerant

describes a microorganism that grows in the presence of oxygen (may require carbon dioxide).

Project: M56


affinity

in immunology, a measure of the attraction or force of association between a single antigenic site and a single antibody to that site (Ka)

Project: I/LA20, I/LA34

NOTE: Affinity is best measured using a monovalent antigen and a monovalent antibody (Fab) fragment.


affinity

the force by which atoms, ions, molecules, prosthetic groups, and particles are attracted or held together in chemical compounds.

Project: NRSCL8, I/LA23


affinity

in Immunology, a measure of the attraction, or force of monovalent association, between a single antigenic determinant and a single antibody-binding site.

Project: I/LA28


affinity

the force of attraction between molecules.

Project: I/LA30


affinity chromatography

a method for separating specific molecules from a heterogeneous mixture by capturing the molecule of interest (target) with a molecule for which the target has a high affinity or binding constant;

Project: I/LA29

NOTE: The capture molecule is attached to a solid phase cross-linked dextran gel material.


affinity constant

(Ka) in Immunology, the equilibrium constant for the receptor + ligand reaction.

Project: I/LA18, LA01, DI01, I/LA28

NOTE 1: Strictly, the term only applies to homogeneous receptors and their ligands. However, polyclonal antibody preparations, which are heterogeneous in their affinity for homogeneous ligands, are often used; NOTE 2: The term also expresses the intrinsic binding strength of a receptor-ligand pair; NOTE 3: The average or mean affinity constants are usually described for polyclonal antisera because of their heterogeneity and polyvalency.


affinity-independent assays

an assay is affinity-independent whenever the product of Ka and Rf (molar concentration of binding sites) is greater than 10; when this occurs, the assay is considered to be in receptor excess.


agar

a gelatin like material extracted from various red algae, used for solidifying certain media used for the culture of microorganisms and other purposes.

Project: POL1/2


agar dilution susceptibility test

an in vitro antimicrobial susceptibility test method conducted using serial concentrations of an antimicrobial agent incorporated into an agar growth medium in separate petri dishes.


agar dilution susceptibility test

an in vitro antimicrobial susceptibility test method conducted using serial concentrations of an antimicrobial agent incorporated into an agar growth medium in separate Petri dishes that are inoculated with one or more properly spaced, standardized bacterial suspensions to determine the minimal inhibitory concentration.

Project: VET05


agar dilution susceptibility test

an in vitro antimicrobial susceptibility test method conducted using serial concentrations of an antimicrobial agent incorporated into an agar growth medium in separate Petri dishes that are inoculated with a bacterial suspension to determine the minimal inhibitory concentration (MIC).

Project: VET02


agar dilution technique

the method of antimicrobial susceptibility testing that is based on preparation of agar plates containing various concentrations of antimicrobial agents on which a defined inoculum of microorganisms is inoculated and then incubated and observed for growth.

Project: M43


agar disk diffusion susceptibility test

an in vitro antimicrobial susceptibility test conducted using disks impregnated with a specified single concentration of an antimicrobial agent applied to the surface of an agar medium that has been inoculated with the test organism;

Project: VET05, VET02

NOTE 1: The diameter of the zone of growth inhibition that results from the diffusion of an antimicrobial agent from the disks is measured with calipers or ruler and recorded in millimeters; NOTE 2: The diameter of the zone of growth inhibition that results from the diffusion of an antimicrobial agent from the disks is measured with calipers or a ruler and recorded in millimeters. Zone diameters are recorded and interpreted according to CLSI standards.


agarose

a carbohydrate material used for preparing gels for the electrophoresis step used in Southern blotting.

Project: MM02


agent

a substance or entity that causes a reaction or response. See specific modifier (eg, infectious agent or etiologic agent).

Project: NRSCL8


agglutination

the aggregation of particulate matter as a result of antigen-antibody reaction;

Project: DI01

NOTES: a) Particles include bacteria, erythrocytes or other cells, or synthetic particles, such as plastic and/or glass beads coated with antigens or antibodies; b) Aggregation is usually primarily dependent on surface reactions mediated either by antigens or by antibodies that are physically or chemically attached to the particulate surfaces; agglutination or clumping of the particles follows as a secondary immune reaction.


agglutination inhibition

the process by which soluble antigen in the test medium reacts with soluble antibody, thereby inhibiting agglutination of indicator particles;

Project: DI01

NOTE 1: In agglutination inhibition assays, particle-bound and soluble antigen compete for soluble antibody; NOTE 2: With viral hemagglutination inhibition, host antibodies resulting from a specific infection are the most common forms of agglutination inhibition. In this case, viral-specific antibodies block the sites on the virus that agglutinate erythrocytes (DI1).


agglutinin

usually, an antibody that mediates the phenomenon of agglutination;

Project: DI01

NOTE 1: Agglutinins are present as isolated molecules in solution in serum, plasma, or other biological fluids being assayed, but they may first be attached (in reverse passive agglutination) or complexed to the particulate surface; NOTE 2: Some viruses (particularly the myxoviruses, such as influenza) agglutinate erythrocytes nonimmunochemically; hence, they are considered agglutinins, even though they are not antibodies (Cf. DI1).


aggregation

platelet clumping, largely mediated by fibrinogen or von Willebrand factor binding to the platelet receptor, GPIIb/IIIa (integrin αIIb β3), following activation of intact platelets by agonists or shear stress.

Project: H58


agonist

a substance or protein that can stimulate platelet activation (eg, collagen, adenosine diphosphate [ADP], epinephrine, thrombin, arachidonic acid, ristocetin).

Project: H58


agreement

the proportion of specimens where results obtained using a new test and those obtained using an imperfect standard agree; overall percent agreement, agreement of new test with imperfect standard-positive, and/or agreement of new test with imperfect standard-negative. The following terms relate to the term “agreement” in the context of this document: negative percent agreement (NPA) – the proportion of nonreference standard negative samples in which the new test is negative; positive percent agreement (PPA) – the proportion of nonreference standard positive samples in which the new test is positive; overall percent agreement – the proportion of samples in which the new test and the nonreference standard give the same outcome.

Project: MM10, I/LA33


aid in diagnosis

as defined by the US Food and Drug Administration, an adjunct assay that is used in conjunction with clinical indications. The assay’s threshold value has been validated and device performance, such as negative predictive value, has been demonstrated. The assay’s relative sensitivity and specificity may or may not be established.

Project: H59


air changes

the amount of air it takes to replace existing air in a space over a specific time.

Project: QMS04


air pressure

the force exerted on a surface by the weight of air above it; more air is greater pressure, less air is lower pressure

Project: QMS04

NOTE: Air pressure is used in heating, ventilation, and air conditioning to determine airflow from one area to another, as air moves naturally from areas of greater pressure to areas of lower pressure.


airborne (transmission)

occurs by dissemination of either airborne droplet nuclei or small particles in the respirable size range containing infectious agents that remain infectious over time and distance.

Project: M29


airborne precautions

applies to patients known or suspected to have serious illnesses transmitted by airborne droplet nuclei.


airborne transmission

the spread of infection by inhalation of droplet nuclei or dust particles containing infectious agents.


alarm threshold

the glucose concentration that, when attained or predicted by the device, initiates an event alarm.

Project: POCT05


alert

a communication that describes a problem, hazard, or risk that may exist with or may be associated with the use of a specific product which may have adverse health consequences;

Project: QMS10

NOTE 1: For the purpose of QMS10, the term Alerts is used to describe any form of communication from an external source. These may include alerts, field corrections, hazards, notifications, recalls (mandatory or voluntary), and/or withdrawals; NOTE 2: This communication is typically issued by the product manufacturer, but may be issued by a regulatory agency or an independent source.


alert index

indicates the lowest tested concentration of hemoglobin, bilirubin, and lipemia/turbidity at which the analyte concentration would be significantly falsely increased or decreased;

Project: C56

NOTE: This is also known as the threshold level.


alerts

notifications that may appear to the users of a computerized physician or provider order entry system

Project: GP49

NOTE 1: Some alerts are informational. For example, an alert may highlight a penicillin allergy when the provider is attempting to order penicillin or a similar drug. Some of the alerts may indicate deterrents to what is viewed as a best practice, but the provider has the ability to override the alert in the computer; NOTE 2: This type of clinical decision support tool has colloquially been termed a “soft stop”; NOTE 3: Examples include simple notification that a test has already been ordered or is expensive; the provider is then prompted to proceed or cancel the order.


algorithm

a set of rules for solving a problem in a finite number of steps, as for finding the greatest common divisor.

Project: M35, AUTO10


algorithm

a set of rules or calculations applied to test data that generate an interpretable or reportable result.

Project: MM17, I/LA28


algorithmic testing

recommended testing pathway in which the next step is based on a previous test’s result

Project: GP49

NOTE 1: These pathways are usually more complicated than simple, single-step reflex testing; NOTE 2: Testing algorithms are commonly included in published documents or may less commonly occur automatically once the algorithmic cascade is ordered.


alignment

the process of lining up two or more sequences for the purpose of assessing the percent identity shared between sequences.

Project: MM18


alignment

the process of lining up two or more sequences for the purpose of assessing the percent identity shared between sequences and/or constructing a contiguous sequence from overlapping smaller segments.

Project: MM09


aliquot

in quantitative analysis, comprising a known fraction or measured portion of a whole and constituting a sample of the whole;

Project: NRSCL8

NOTE: Usually, the aliquot is expressed as a stated volume or mass, less often as the fraction of the whole.


aliquot

a portion of an original specimen collected by or submitted to a laboratory for testing;

NOTE: Aliquots are removed from the specimen and tested, and aliquotting from a specimen must be done in a manner that preserves the integrity of the original specimen.


aliquot

in Chemistry, comprising a known fraction of a whole and constituting a sample;

NOTE: For example, an aliquot quantity of acid for analysis.


aliquot

a portion of an original specimen collected by or submitted to a laboratory for testing

Project: C52

NOTE 1: Aliquots are removed from the specimen and tested, and aliquotting from a specimen should be done in a manner that preserves the integrity of the original specimen; NOTE 2: A sample is an aliquot of a specimen.


aliquot

in Automation, a portion of a specimen placed in a separate container to facilitate concurrent testing or to hold in reserve for future use;

Project: AUTO01, AUTO02, AUTO07, QMS04, AUTO12

NOTE 1: The portion of the specimen is typically removed from the original specimen after initial processing, such as centrifugation, to obtain serum or plasma samples, and is considered to be chemically identical to all other subdivisions of an original sample of serum, plasma, urine, cerebral spinal fluid, etc.; NOTE 2: In all circumstances in which the aliquot may be removed from the system in which it is prepared and then handled or transported, it is necessary to identify the aliquot as an individual specimen distinct from the original specimen in a collection container labeled with a unique identifier that may be linked to or associated with the primary collection container.


aliquot container

a container or tube that holds a portion or aliquot of a specimen;

Project: AUTO12

NOTE: See aliquot.


aliquot tube

See "aliquot container."

Project: AUTO12


aliquotter

part of an automation line where the samples are separated into one or more secondary tubes.


alkalis

substances with a pH higher than 7

Project: QMS04

NOTE: Alkalis are also referred to as “bases” and can cause severe burns to the skin


all base accuracy

calculated by determining the percentage of the bases called that agree with the expected base call in the reference sequence.

Project: MM09


all hazards planning

detailed guidelines worked out in advance for addressing emergency situations;

Project: GP36

NOTE: All hazards planning, as used by emergency planners, promotes developing one general emergency operations plan intended to cover many different types of incidents. It relies on the core concept that many planned response actions are the same, irrespective of the type of disaster inciting them.


allele

one of the alternative forms of a gene that may occupy a given locus;

Project: MM10, MM12, MM01, I/LA29, MM17, MM22

NOTE 1: In genetics, any of several forms of a gene that is responsible for hereditary variation; NOTE 2: One of the alternate forms of a polymorphic DNA sequence that is not necessarily contained within a gene; NOTE 3: A pseudoallele is an almost identical sequence to the allele found elsewhere in the genome.


allele

in genetics, any of several forms of a gene that is responsible for hereditary variation;

Project: MM09, MM03

NOTE: A pseudoallele is an almost identical sequence to the allele found elsewhere in the genome.


allele

alternative forms of a gene at a given locus.

Project: NBS05


allele dropout

occurs when a sample is genotyped and at least one allele is not present. This can occur due to amplification failure if the template DNA concentration is low or if a primer fails to bind due to a sequence change in the primer binding site. It can also occur if an allele falls outside of the defined size or range analysis of a particular allele (see National Forensic Science Technology Center).

Project: MM01


allele-specific oligonucleotide

(ASO) a nucleic acid probe of short length, exactly complementary to either the normal or one of the mutant sequences of a target gene region, most often used for the detection of point mutations;

Project: MM01, MM10, MM12

NOTE: An allele-specific oligonucleotide is a short sequence of DNA that is designed with 100% homology to a specific form of the gene but has noncomplementary nucleotides at the 3′ end to prevent polymerase chain reaction amplification of similar, but not identical, alleles.


allele-specific polymerase chain reaction

amplification of specific alleles, or DNA sequence variants, at the same locus. Specificity is achieved by designing one or both polymerase chain reaction primers so that they partially overlap the site of sequence difference between the amplified alleles.

Project: MM19


allele-specific primer extension

a solution-based, sequence-specific enzymatic reaction technology that can be used to assay multiple alleles in a single tube; an enzymatic DNA polymerization reaction that determines the genotype of a target.

Project: MM22


allelic imbalance

in a diploid organism with alleles A and B, when neither the A nor B allele frequency does not equal zero or the B allele frequency does not equal 50%;

Project: MM21

NOTE: Refers to the state in which one allele is present at a greater frequency than the other. This may be due to copy number changes or to absence of heterozygosity that is copy number neutral.


allelic ratio

the ratio of a specified allele to the total number of alleles, normally expressed as a fraction;

Project: MM17

NOTE 1: For example, if a specific allele represents 40% of the total alleles found at a given locus, the allelic ratio is 0.4; NOTE 2: Allelic ratio is synonymous with allele frequency.


allergen

an immunogen that when introduced into a host elicits the formation of IgE antibodies

Project: DI01, I/LA20, I/LA34

NOTE 1: To illustrate, the whole cat is not the allergen. Fel d 1 is an allergen produced by the cat, which is the allergen source or allergen carrier; NOTE 2: CLSI database I/LA37 contains a list of identified allergen specificities that are presented as allergen extracts (physiological extractions of biological source material that is complex in its protein, carbohydrate, and lipid composition) and individual native and recombinant allergen molecules that have been documented by studies involving human IgE antibody binding.


allergen extract

a mixture of molecules, typically, proteins, glycoproteins, lipoproteins, or protein-conjugated chemicals/drugs that have been solubilized from a defined (usually biological) source and that a portion of which can elicit an immunoglobulin E antibody response in exposed persons

Project: I/LA20, I/LA34

NOTE 1: In ILA20, Appendix A contains a list of available allergen extracts; NOTE 2: Drugs tend to be single component allergenic sources; however, when in the presence of incipients, they can be viewed as a complex mixture of components; NOTE 3: CLSI database I/LA3720 contains a list of available allergen extracts. Allergen extracts have historically been referred to as “allergens” by diagnostic reagent manufacturers. This common practice should be replaced by the use of “allergen extract” to distinguish it from an allergen molecule.


allergen molecule

individual native or recombinant allergen that has unique molecular and structural properties, including a defined molecular weight, isoelectric point, carbohydrate composition, nucleotide and/or amino acid sequence, and reactivity to a monospecific or monoclonal antibody. In addition, the allergenic property of the “major allergens” of a given allergen specificity needs to be verified by its ability to bind to immunoglobulin E antibody and/or induce a positive skin test or histamine release from basophils from individuals who are clinically allergic to that allergen specificity

Project: I/LA20

NOTE: CLSI database I/LA37 contains a list of available allergen molecules.


allergen potency

the composite concentration of all of the allergenic epitopes within an allergen that together produce a defined biological (type 1 hypersensitivity, immunoglobulin E-mediated) response in allergic persons

Project: I/LA20, I/LA34


allergen reagent

the component of the immunoglobulin E (IgE) antibody assay reagent that contains allergen either bound to a solid phase (immobilized allergen, also called an allergosorbent) or in solution phase (liquid allergen, labeled or unlabeled);

Project: I/LA20

NOTE: These reagents, when prepared with an allergen extract, are typically composed of heterogeneous mixtures of proteins or chemicals/drugs that are conjugated or bound to carrier proteins. More recently, purified allergen molecules representing native allergens or recombinant allergens have been successfully used in place of allergen extracts as the key assay reagent that defines the specificity of the analytical measurement. Ideally, the allergen reagent should contain all of the allergenic epitopes of that specificity that elicit IgE antibodies in humans.



allergen reagent

the component of the IgE antibody assay that contains allergen either bound to a solid phase (immobilized allergen) or in solution phase (liquid allergen, labeled or unlabeled)

Project: I/LA34

NOTE: These reagents, like the allergen extracts from which they are derived, are typically composed of heterogeneous mixtures of proteins or chemicals/drugs that are conjugated on carrier proteins. More recently, purified components of native allergens or recombinant allergens have been successfully used. Ideally, the allergen reagent should contain all of the allergenic epitopes of that specificity that elicit IgE antibodies in humans.


allergen source material

the starting raw material from which allergenic extracts are obtained

Project: I/LA20

NOTE: This material may or may not have been physically processed to remove extraneous, nonbiological materials, and it is typified by materials such as raw pollen, animal hair, mold cultures, drugs, venoms, foodstuffs, or recombinant expressed proteins.


allergenic epitope

a submolecular structure or surface on the allergenic molecule primarily responsible for immunoglobulin E antibody binding

Project: I/LA20


allergenic epitope

a submolecular structure primarily responsible for IgE antibody binding on the drug molecule.

Project: I/LA34


allergenic molecule

a single component (typically, a protein, glycoprotein, or lipoprotein) of a biological substance that is highly purified from extracts of native, biological material or produced by recombinant molecular biology techniques or other means for artificial epitope production methods.

Project: I/LA34


allergenicity

the ability of a biomolecule to elicit an IgE antibody response in an immunocompetent host, which mediates type I hypersensitivity (allergic) reactions.

Project: I/LA34


allergosorbent

a solid phase material to which allergenic molecules are attached by covalent coupling methods or adsorption.

Project: I/LA20, I/LA34


alloantibodies

antibodies directed at epitopes that are present in some but not all members of the same species;

Project: I/LA29

NOTE: In the HLA setting, the antigens encoded by HLA genes are very polymorphic, with many variations of the genes found at the same loci. An individual can make an immune response against the epitopes that differ in another individual.


alloantibody

an antibody that reacts with an antigen from a genetically different individual of the same species. See also antiglobulin.

Project: NRSCL8


alloantigen

an antigen found in members of the same species (CF. DI1.)

Project: DI01


allogeneic

in Immunology, cells, tissues, etc., that are related but sufficiently dissimilar in genotype to interact antigenically (RHUD1.7CD)(Cf. DI1).

Project: DI01


allogeneic

denoting or relating to cells or tissues from individuals belonging to the same species but genetically dissimilar (hence, immunologically incompatible).

Project: MM19


allograft

a tissue or organ obtained from one member of a species and grafted to a genetically dissimilar member of the same species;

NOTE: Syn. Homograft ( DI1).


alloimmunization

the immunization of one animal with antigens from another of the same species (Cf. DI1)

Project: DI01


allophycocyanin

(APC) one of several phycobiliprotein-based fluorochromes, derived from algae or bacteria, which can be conjugated to antibodies for use in immunophenotyping;

Project: H43, H42

NOTE: APC has a molecular weight of roughly 80 000 daltons. Although optimally excited at 655 nm, there is sufficient excitation at 635 nm to produce a useable signal at 660 nm when excited with a helium-neon (HeNe) or diode laser.


allophycocyanin

(APC) a fluorescent protein derived from cyanobacteria or red algae that is excited by a red (632 nm) laser (eg, HeNe) on many flow cytometers;

Project: I/LA26

NOTE: APC is excited maximally at approximately 650 nm with an emission maximum at 660 nm.


allotype

an antibody of a given class having certain molecular sites shared by only some members of a species and, therefore, acting as an antigen to other members of the same species (RHUD1.7CD).


allowable difference

the magnitude of analytical deviation, from all sources, that a user can tolerate in a testing system and still meet the medical requirements of the test;

Project: EP06

NOTE: The allowable difference (error) boundaries (for a single observation) are represented by the target value of the specimen plus or minus the allowable error amount.


allowable drift

the maximum change in the quantity value by which product performance is kept within limits specified by the manufacturer.

Project: EP25


allowable total error

the amount of error that can be tolerated without invalidating the medical usefulness of the analytic result.

Project: MM10


allowable total error

(TEa) an analytical quality goal that sets a limit for both the imprecision (random error) and bias (systematic error) that are tolerable in a single measurement or single test result

Project: C24

NOTE 1: Such criteria are often provided by external quality assessment (proficiency testing) programs, government regulations, or based on biologic variation, or defined medical requirements; NOTE 2: For quality control (QC) planning, it is assumed there are no specimen-specific influences because they are a component of overall method performance that is not monitored by a statistical QC strategy; NOTE 3: Some publications denote allowable total error as "ATE."


allowable total error

(ATE) an analytical quality goal that sets a limit for both the imprecision (random error) and bias (systematic error) that are tolerable in a single measurement or single test result

Project: EP21

NOTE: Also called total error allowable (TEa).


allowable total error zone

region on the error grid plot corresponding to measurement errors that are regarded as unlikely to cause potential patient harm.

Project: EP27


alpha error

probability of falsely rejecting the null hypothesis when it is true.

Project: EP31


alpha error

probability of falsely rejecting the null hypothesis that a substance does not interfere when it is true.

Project: EP07


alpha globulin

one of several groups of blood plasma proteins, divided into fractions, based on electrophoretic mobility somewhat slower than albumin.

Project: DI01


alpha level

the probability that one will reject the null hypothesis when it is true;

NOTE: The alpha level is often set at 5 or 1 percent.


alternate care facility

nonhospital facility that assumes the function of outpatient, urgent, or inpatient care during an emergency to promote expansion of community bed capacity and care.

Project: GP36


alternate site testing

sampling from anatomical sites other than the fingertip, ie, forearm, upper arm, thigh, calf, or palm, for blood glucose monitoring.

Project: POCT13


alternative assessment

system for determining the reliability of tests for which proficiency testing is either not available or not required, including ungraded and/or educational challenges; split sample analysis with reference or other laboratories; split samples with an established in-house method; assayed material; regional pools; clinical validation by chart review; or other suitable and documented means

Project: QMS24


alternative assessment

(proficiency testing [PT]) a system for determining the reliability of tests for which formal PT programs are either not available or not appropriate, or when participation is not required by regulation. Appropriate alternative assessment procedures may include: participation in sample exchange with another laboratory performing a similar test; ungraded/educational challenges; split sample analysis with reference or other laboratories; split samples with an established in-house method; clinical validation by chart review; or other suitable and documented means. It is the responsibility of the laboratory director to define such alternative assessment procedures, as applicable, in accordance with good clinical and scientific laboratory practice.

Project: MM14


alternative hypothesis

in interference testing, a statement to be tested at a specified power, that a substance causes interference greater than a specified limit (dalt)

Project: EP07


alternative pathway

a series of complement interactions that is not activated by antigen-antibody complexes and does not involve complement components C1, C2, or C4 (Cf DI1).

Project: DI01


alveolar arterial oxygen tension difference

[PO2 (A - aB)//PAO2 - PaO2 //(A - a) PO2// A - a DO2] the difference between the partial pressure of oxygen in alveolar gas compared to that of arterial blood (Cf. C12, C25). See also gas exchange indices.

Project: C25, C12


alveolar oxygen tension

(PO2 (A)//PAO2) the partial pressure of oxygen in alveolar gas.

Project: C12, C25

NOTE: Estimated by the standardized “alveolar air equation,” this quantity is required for calculation of gas exchange indices, such as the oxygen tension gradient and ratio, as well as being useful as an internal (within-sample) quality control check. See also gas exchange indices.


amateur radio

international hobby composed of volunteer operators, licensed (in the United States) under the Amateur Radio Service;

Project: GP36

NOTE 1: Amateur Radio Service is a communications service as defined by the Federal Communications Commission; NOTE 2: Also known as “ham radio”; NOTE 3: US and Canadian amateur operators often assist in emergencies, are usually organized through local clubs and organizations, and are often affiliated with the Amateur Radio Emergency Service.


amino acid

an organic compound containing two major functional groups: an amino group (−NH2) and a carboxylic group (−COOH)

Project: NBS04

NOTE: Most physiologically important amino acids are those in which the amino group and the carboxylic acids are both attached to the carbon atom in position 2 (α carbon).


amniotic fluid

the fluid surrounding a fetus within the amnion.

Project: C58


amount of substance

the number of moles of the substance.

Project: NRSCL8


amplicon

(amplification product) the relatively low-molecular-weight products created from a target amplification reaction

Project: MM03, MM18, MM17, M55, MM19, MM22

NOTE 1: Amplicons will be double-stranded DNA if created by a polymerase chain reaction and will be primarily single-stranded RNA if created in a nucleic acid sequence-based amplification or transcription-mediated amplification reaction; NOTE 2: PCR (polymerase chain reactions) produce double-stranded DNA amplicons. Nucleic acid sequence–based amplification (NASBA) or transcription-mediated amplification (TMA) reactions produce primarily single-stranded RNA amplicons.


amplicon

the product of polymerase chain reaction; a fragment of DNA that has been synthesized using amplification techniques.

Project: NBS06, MM16, MM17


amplicons

the DNA products of a polymerase chain reaction.

Project: MM05


amplification

the enzymatic replication in vitro of a target nucleic acid;

Project: MM12, MM01, MM22, MM09

NOTE: The polymerase chain reaction is a commonly used method of amplification.


amplification

the use of substances that directly increase signal in proportion to quantity of analyte, or directly increase the quantity of the analyte;

Project: I/LA18, MM10

NOTE: Examples include avidin biotin labels and substrates which, following hydrolysis by an enzyme label, produce fluorescent components.


amplification

the process of producing multiple copies of a specific segment of DNA, usually a gene to obtain enough material for further study.

Project: MM18


amplification

1) the process of using substances that linearly increase signal in proportion to quantity of measurand; 2) logarithmic amplification – amplification with a response that is logarithmic rather than linear.

Project: MM05


amplification bias

a skewing of the distribution of polymerase chain reaction products away from the relative nucleic acid template quantities present in an input sample due to unequal amplification;

Project: MM09

NOTE: In massively parallel sequencing, amplification bias can result in over- or under-representation and/or reduced sequence quality at individual genetic loci.


amplification product

(amplicon) the relatively low molecular weight products created from a target amplification reaction;

Project: MM10

NOTE: Amplicons will be double-stranded DNA if created by a PCR reaction and will be single-stranded RNA if created in a NASBA or TMA reaction.


amps

short for amperes, which is a unit of measurement for electrical current.

Project: QMS04


analysis

the procedural steps performed that enable determination of the kind or the amount of an analyte in a specimen (ISO 15196)

Project: ISO 15196


analysis

the procedural steps performed that enable determination of the kind or the amount of an analyte in a specimen (ISO 15196)

Project: ISO 15196


analysis boundary

dividing line (cursor) placed on a histogram or dual-parameter display that discriminates events that are considered positive or reactive with a particular antibody from those that are negative or nonreactive;

Project: H42, H43

NOTE: An analysis boundary is most commonly set on a histogram obtained using a negative control antibody so that a fixed small proportion of events is considered positive.


analyte

component represented in the name of a measurable quantity (ISO 17511)

Project: M52, GP47, H48, QMS24, I/LA20, ISO 17511, MM13, X05, MM10, MM03, C53, ISO 18153, EP06, EP10, MM07, EP15, ILA23, ILA25, ILA24, MM14, HS02, POCT07, H59, I/LA28, MM12, MM16, POCT04, C49, ILA21, C54, C50, EP12, H58, POCT05, MM11, H57, MM17, C34, EP18, GP33, GP34, ILA34, EP23, C58, MM19, NBS05, POCT10, MM01, C56, MM20, EP26, MM22, H60, C62, EP15, C57, MM23, POCT06, EP19

NOTE 1: In the type of quantity "mass of protein in 24-hour urine," "protein" is the analyte. In "amount of substance of glucose in plasma," "glucose" is the analyte. In both cases, the long phrase represents the measurand (ISO 17511); NOTE 2: In the type of quantity "catalytic concentration of lactate dehydrogenase isoenzyme 1 in plasma," "lactate dehydrogenase isoenzyme 1" is the analyte. The long first phrase designates the measurand (ISO 18153); NOTE 3: The analyte is the particular component of interest to the patient; NOTE 4: This includes any element, ion, compound, substance, factor, infectious agent, cell, organelle, activity (enzymatic, hormonal, or immunological), or property, the presence or absence, concentration, activity, intensity, or other characteristics of which are to be determined; NOTE 5: As used in this document, the pure molecular or cellular form of the substance to be detected or quantified, independent of the sample matrix in which it is present; NOTE 6: This is the chemical entity/substance that is actually intended to be measured; NOTE 7: Formerly in this document, analyte was used to describe both a single component (analyte) as well as the analyte in its specific matrix (measurand); NOTE 8: Also understood as the characteristic being measured in the test sample; NOTE 9: One or more systematic failure components may contribute to the bias; NOTE 10: Bias is a measure of the degree of trueness; NOTE 11: An estimate of bias is the average value of a series of measurements minus a reference value; NOTE 12: The analyte is the constituent or characteristic of the sample to be measured; NOTE 13: For the diagnostic allergy laboratory, allergen-specific immunoglobulin E molecules may be considered the primary analyte of interest; NOTE 14: In chemistry, “analyte,” or the name of a substance or compound, is a term sometimes used for “measurand.” This usage is erroneous because these terms do not refer to quantities (JCGM 200:2012); NOTE 15: For molecular genetic testing, the nucleic acid target to be detected, characterized, or measured; NOTE 16: In fluorescence in situ hybridization analysis, the analyte could be viewed as the “genomic target” in “the number of genomic targets per cell” (eg, the number of BCR loci detected in a nucleus). It may also be viewed as the “genomic condition” in “the frequency of cells with a particular genomic condition” (eg, the frequency of cells with three BCR loci or the frequency of cells with juxtaposition of the BCR and ABL1 loci). Probe sensitivity and probe specificity are relevant to the first context, while analytical sensitivity and analytical specificity are relevant to the second context; NOTE 17: In microbiology, a substrate or antimicrobial agent being tested to determine microbial identification or antimicrobial susceptibility testing results, respectively.


analyte

component represented in the name of a measurable quantity (ISO 17511)

Project: NBS04

NOTE: For the purpose of NBS04, see biomarker.


analyte

component represented in the name of a measurable quantity (ISO 17511).

Project: NBS07

NOTE: See measurand.


analyte

constituent of a sample with a measurable property (ISO 18113-1)

Project: C24, ISO 18113-1

EXAMPLE: In “mass of protein in 24-hour urine,” “protein” is the analyte and “mass” is the property. In “concentration of glucose in plasma,” “glucose” is the analyte and “concentration” is the property. In both cases, the full phrase represents the measurand (ISO 18113-1)


analyte

substance being measured or detected.

Project: POCT08


analyte

a substance or constituent for which the laboratory conducts testing (US CFR 493; February 28, 1992);

NOTE: This includes any element, ion, compound, substance, factor, infectious agent, cell, organelle, activity (enzymatic, hormonal, or immunological), or property, the presence or absence, concentration, activity, intensity, or other characteristics of which are to be determined.


analyte-specific reagent

(as defined in the United States by the US Food and Drug Administration) antibodies, both polyclonal and monoclonal, specific receptor proteins, ligands, nucleic acid sequences, and similar reagents which, through specific binding or chemical reaction with substances in a specimen, are intended for use in a diagnostic application for identification and quantification of an individual chemical substance or ligand in biological specimens [21 CFR 864. 4020(a)].

Project: MM19


analyte-specific reagents

antibodies, both polyclonal and monoclonal, specific receptor proteins, ligands, nucleic acid sequences, and similar reagents which, through specific binding or chemical reaction with substances in a specimen, are intended for use in a diagnostic application for identification and quantification of an individual chemical substance or ligand in biological specimens;

Project: H43, MM06, I/LA28

NOTE 1: An analyte-specific reagent is the active ingredient of an in-house test (H43); NOTE 2: ASRs can be viewed as having the following characteristics: used to detect a single ligand; no instructions or performance claims; and not promoted for use on specific instruments or in specific tests or test systems. The ASR rule was designed to accomplish several policy objectives: 1) ensuring the quality of materials used as components of in-house laboratory tests, 2) providing appropriate labeling so that health care users would understand the level of test validation. ASRs are intended to be unique reagents that are not marketed in a form that is combined with other reagents or support materials and have not been optimized to work on a proprietary or preoptimized analytical system (one in which the software and hardware has been specifically designed to allow for detection of signals generated by that reagent). Where reagents are marketed in this manner, the reagent is not considered an ASR but a part of a total test system and it should be submitted to an applicable regulatory agency for premarket review. Although it may be possible for an ASR to be used for purposes of allergen-specific IgE testing, to date most if not all existing test systems are configured in such a manner that precludes use of ASRs. Of note, use of ASRs for testing of rare allergens is a particularly problematic practice because it is unlikely that most laboratories could assemble analytical and clinical materials needed to adequately validate such as assay. In contrast to an ASR, a "General Purpose Reagent" (GPR) is "a chemical reagent that has general laboratory application, that is used to collect, prepare, and examine specimens from the human body for diagnostic purposes, and that is not labeled or otherwise intended for a specific diagnostic application." Like ASRs, GPRs are not labeled for a specific clinical or diagnostic use. Because GPRs are not analyte-specific, they should be able to be combined with, or used in conjunction with more than one ASR. In contrast, as stated above, an ASR is a specific chemical component, probe, or antibody that can detect an individual chemical substance or ligand. An ASR is considered the "active ingredient" or "building block" of a laboratory-developed test.


analyte-specific reagents

(ASR) products for use in home-brew testing, which have manufacturer assurances of GMP;

NOTE 1: ASRs must be labeled in accordance with 21 CFR § 809.10(e); NOTE 2: Advertising and promotional materials are regulated by 21 CFR § 809.30(d); NOTE 3: The laboratory that develops an in-house test using the ASRs shall inform the ordering person of the test result by appending to the test report this statement according to 21 CFR § 809.30(e): "This test was developed and its performance characteristics determined by (laboratory name). It has not been cleared or approved by the US FDA."


analytic interference

artifactual increase or decrease in apparent concentration or intensity of an analyte due to the presence of a component or property of the normative clinical sample that reacts nonspecifically with either the detecting reagent or the signal itself.


analytical performance

the sum of all analytical attributes that may be important for a measurement procedure for which the measurand is used for a specific intended use;

Project: EP19

NOTE: Performance specifications usually include analytical sensitivity, specificity, and other parameters.


analytical accuracy

See accuracy.

Project: I/LA28


analytical cross-reactivity

evaluation of the level of nonspecific binding of control and/or test probes to nontargeted analytes that may be present in samples.

Project: MM16


analytical interference

systematic effect on a measurement caused by an influence quantity which does not by itself produce an indication, but which causes an enhancement or depression of the indication (ISO 15193)

Project: ISO 15193


analytical measurement range

(AMR) the range of analyte values that a method can directly measure on the sample without any dilution, concentration, or other pretreatment that is not part of the typical assay process;

Project: C54, H57, POCT09

NOTE: See measuring interval.


analytical measurement range

(AMR) range of analyte values that a method can directly measure on the specimen without any dilution, concentration, or other pretreatment, not part of the usual assay procedure;

Project: C50, MM06

NOTE: See measuring interval.


analytical measuring interval

See measuring interval.

Project: C62


analytical measuring interval

(AMI) a set of values of quantities of the same kind that can be measured by a given measuring instrument or measuring system with specified instrumental uncertainty, under defined conditions;

Project: C34, H26, GP26

NOTE: It is sometimes called the analytical measurement range (AMR), which is the range of analyte values that a method can directly measure on the specimen without any dilution, concentration, or other pretreatment not part of the usual assay process.


analytical method

NOTE: See and use "measurement procedure."

Project: EP06, I/LA21, I/LA23


analytical performance goal

the analytical performance (ie, bias, imprecision, nonspecificity) of an assay desired for a particular clinical application (ISO 15196)

Project: ISO 15196


analytical phase

laboratory activities including specimen processing, reagent preparation, and specimen analysis

Project: NBS04


analytical portion

portion of material taken from the analytical sample and on which the measurement is actually carried out, either directly or following dissolution (ISO 15193)

Project: ISO 15193

NOTE: The analytical portion is taken directly from the primary sample or laboratory sample if no preparation of these is required. The analytical portion is sometimes dissolved to give an analytical solution before being exposed to themeasuring device (ISO 15193).


analytical process

the technical process including the operation of equipment and the performance of the defined steps of a testing procedure designed to produce data including the examination of patient samples.

Project: POCT10


analytical result

in EP06, the final result of a measurement on a test specimen;

Project: EP06

NOTE: The result is usually in concentration or activity units; it is assumed that the measurement procedures to be evaluated by the procedures in EP06 are quantitative methods that yield a numerical output.


analytical run

a set of specimens that are analyzed in a time period within which the measurement system is considered to have stable trueness and precision

Project: C50, NBS04

NOTE: An analytical run usually consists of both quality control specimens and patient specimens. An analytical run is sometimes referred to as “batch analysis.”


analytical sample

sample prepared from the laboratory sample and from which analytical portions can be taken (ISO 15193)

Project: ISO 15193

NOTE: The analytical sample can be subjected to various treatments before an analytical portion is taken (ISO 15193).


analytical sensitivity

quotient of the change in an indication and the corresponding change in the value of a quantity being measured (ISO 15193)

Project: MM21, POCT17, I/LA20, ISO 15193, M55, M53, MM19, MM01, MM20, MM14, MM07, MM22, MM03, MM23, EP19

NOTE 1: The term "analytical sensitivity" is not intended to be used as a synonym for "detection limit" (ISO 15193); NOTE 2: ISO/IEC Guide 99:2007 uses the term "sensitivity of a measuring system" (ISO 15193); NOTE 3: The amount of measurand being detected by the measurement procedure at a given detection frequency; NOTE 4: See seroconversion sensitivity; NOTE 5: The sensitivity may depend on the value of the stimulus; NOTE 6: The sensitivity depends on the imprecision of the measurements of the sample; NOTE 7: The analytical sensitivity of a measuring system is the slope of the calibration curve; NOTE 8: Analytical sensitivity should not be used to mean detection limit or quantitation limit, and should not be confused with diagnostic sensitivity (modified from ISO 18113-1); NOTE 9: In qualitative testing, analytical sensitivity is defined as the test method’s ability to obtain positive results in concordance with the positive results obtained by the reference method; NOTE 10: In fluorescence in situ hybridization (FISH) analysis, analytical sensitivity is most often used to describe the lowest frequency of cells with a particular abnormal genomic composition that can be detected by the FISH assay. In this context, analytical sensitivity is equivalent to the limit of detection; NOTE 11: For the purposes of microbial detection, analytical sensitivity is equivalent to limit of detection; NOTE 12: The sensitivity depends on the imprecision of the assay; NOTE 13: If the true sensitivity of a device is better than the reference method, its apparent specificity will be less and the level of apparent false-positive results will be greater; NOTE 14: In genotyping or DNA sequencing, the limit of detection is the lowest concentration of the target nucleic acid that can be reproducibly measured which exceeds the blank sample with no analyte. It may be below the linear range of the assay; NOTE 15: The analytical sensitivity of an assay that detects somatic mutations depends directly on both the number/percentage of nucleated tumor cells in the specimen to be tested and the number/percentage of tumor cells with mutations; NOTE 16: The analytical sensitivity of a solid tumor assay also relates to the lowest percentage of nucleated tumor cells that would be suitable for obtaining reliable results; NOTE 17: The term “analytical sensitivity” has been historically used to describe the lowest amount of a given substance in a biological specimen that is detectable in an assay system; NOTE 18: Throughout I/LA20, the lower limit of quantitation and not “analytical sensitivity” is used to indicate the lowest amount of total or allergen-specific immunoglobulin E antibody in a sample that can be detected by immunoassay with a stated probability and defined accuracy. See lower limit of quantitation.


analytical sensitivity

in quantitative testing, the change in response of a measuring system or instrument divided by the corresponding change in the stimulus;

Project: MM06

NOTE 1: The sensitivity may depend on the value of the stimulus; NOTE 2: The sensitivity depends on the imprecision of the measurements of the sample; NOTE 3: If the true sensitivity of a device is better than the reference method, its apparent specificity will be less and the level of apparent false-positive results could be greater.


analytical sensitivity

the proportion of biological samples that have a positive test result or known variant and that are correctly classified as positive;

Project: MM09

NOTE 1: The overall analytical sensitivity is a measure related to the final assembled sequence; NOTE 2: For nucleic acid sequencing, it is sometimes used to refer to the detection limit.


analytical sensitivity

quotient of the change in a measurement indication and the corresponding change in a value of the quantity being measured (modified from JCGM 200:2012);

Project: EP17

NOTE 1: VIM uses the term "sensitivity of a measuring system"; NOTE 2: The analytical sensitivity of a measuring system is the slope of the calibration curve; NOTE 3: Analytical sensitivity should not be used to mean detection limit or quantitation limit, and should not be confused with diagnostic sensitivity (modified from ISO 18113-1).


analytical solution

solution prepared prior to measurement by dissolving an analytical portion in a liquid or solid material, with or without reaction (ISO 15193)

Project: ISO 15193


analytical specificity

ability of a measurement procedure to determine solely the quantity it purports to measure (ISO 15193)

Project: MM21, POCT17, I/LA20, ISO 15193, MM01, MM20, MM07, MM22

NOTE 1: The ability of a measurement procedure to measure solely the measurand (ISO 17511); NOTE 2: The ability of a measurement procedure to distinguish the target sequence(s)/allele/mutation(s) from other sequences/alleles in the specimen/genome; NOTE 3: Specificity of a measurement procedure should not be confused with diagnostic specificity; NOTE 4: Specificity is the ability of an analytical method to determine only the component it purports to measure; the extent to which the assay responds only to (all subsets of) a specified analyte and not to other substances present in the sample; NOTE 5: Analytical specificity refers in general to the ability of an assay to measure one particular substance, rather than others, in a sample.  Applied to immunoglobulin E (IgE) assays with single allergens, “one particular substance” would indicate the repertoire of allergen-specific IgE to “one particular allergen molecule”; NOTE 6: In the previous editions of I/LA20, analytical specificity of IgE-detecting assays was solely linked to the capability to selectively measure IgE, instead of other immunoglobulin classes or subclasses (eg, immunoglobulin G, immunoglobulin M). This definition refers to the “antibody-related analytical specificity (selectivity)” of IgE-detecting assays and is still an important definition for modern immunoassays; NOTE 7: Allergen molecules for quantifying allergen-specific IgE will limit the detected IgE repertoire. Only antibodies binding to the selected molecule (eg, major cat allergen Fel d 1) will be detected instead of all allergen source-specific (eg, cat-specific) antibodies. Thus, the use of allergen molecules increases analytical specificity compared to the broad allergen-specific IgE repertoire directed toward a complex mixture of proteins in an extract (eg, from cat dander). This new definition refers to the “allergen-related analytical specificity (selectivity)” of IgE-detecting assays; NOTE 8: The term “allergen-related analytical specificity (selectivity)” is particularly useful to understand and justify the concept of species-specific vs crossreactive IgE antibodies toward defined allergen molecules. In case of particular physicochemical properties of certain allergen molecules (eg, high pH and digestion stability, high abundance in an allergen source), IgE detection with these molecules might be helpful to identify risk-associated allergen-specific IgE responses.



analytical specificity

ability of a measurement procedure to measure solely the measurand (ISO 17511)

Project: ISO 17511, EP07, H44, H56, I/LA21, C50, GP16, MM17, M55, I/LA28, M53, MM19, H60, MM23, EP19

NOTE 1: Lack of specificity may be called analytical interference; NOTE 2: A type of interference in immunochemistry measurement procedures may be cross-reactivity; NOTE 3: Specificity of a measurement procedure should not be confused with diagnostic specificity; NOTE 4: Specificity is the ability of an analytical method to determine only the component it purports to measure; the extent to which the assay responds only to (all subsets of) a specified analyte and not to other substances present in the sample; NOTE 5: Within the context of this guideline, specificity refers to an assay that is specific for IgE and shows no cross-reactivity of the antihuman IgE reagent with other classes of human antibodies (eg, IgG, IgA, IgM, and IgD). Tests of reagent specificity shall demonstrate that the antibody being measured is IgE and that it is specific for the allergen of interest based on soluble allergen inhibition studies. The specific IgE assay system should be tested for interfering substances, including but not limited to, lipids, hemoglobin, and medications commonly used by allergic patients, and any known interference should be identified in the manufacturer’s product literature; NOTE 6: In quantitative testing, the ability of a measurement procedure to determine only the component it purports to measure or the extent to which the assay responds only to all subsets of a specified analyte and not to other substances present in the sample; NOTE 7: For qualitative or semiquantitative assays, it is the method’s ability to obtain negative results in concordance with negative results obtained by the reference method; NOTE 8: In Immunology, specificity is an antiserum quality defining its reactivity with defined antigens and lack of specificity is the inaccuracy introduced by cross-reacting and/or interfering substances, because cross-reacting substances compete with the analyte for antibody-binding sites; NOTE 9: Analytical specificity of an immunohistochemical assay is largely dependent on the characteristics of the primary antibody in the total test system; NOTE 10: It denotes freedom from interference by any element or compound other than the analyte; NOTE 11: Specificity has no numerical value in this context.


analytical specificity

ability of a measurement procedure to determine solely the measurable quantity it purports to measure (modified from ISO 17511)

Project: MM10, EP07, I/LA02, I/LA21, I/LA23, MM12, I/LA29, POCT05

NOTE: The ability of a measurement procedure to distinguish the target sequence(s) or allele or mutation(s) from other sequences/alleles in the sample or genome.


analytical specificity

in quantitative testing, the ability of a measurement procedure to determine only the component it purports to measure or the extent to which the assay responds only to all subsets of a specified analyte (measurand) and not to other substances present in the sample; for qualitative or semiquantitative tests, the method’s ability to obtain negative results in concordance with negative results obtained by the reference method; in Immunology, specificity is an antiserum quality defining its reactivity with defined antigens and lack of specificity is the inaccuracy introduced by cross-reacting and/or interfering substances, because cross-reacting substances compete with the analyte for antibody-binding sites;

Project: MM03, H20, MM06

NOTE: For qualitative or semiquantitative tests, analytical specificity is defined as the method’s ability to obtain negative results in concordance with negative results obtained by the reference method.


analytical specificity

the ability of a test to distinguish target sequences, alleles, or variants from other sequences of alleles in the specimen or genome being analyzed;

Project: MM09

NOTE: For nucleic acid sequencing, it refers to the capacity to differentiate the targeted sequence from other sequences that may be present (eg, pseudogenes). The overall analytical specificity is measured relative to the final assembled sequence.


analytical validation

assessment of performance characteristics of an assay, including accuracy, precision, specificity, limits of detection and quantitation, linearity and range, ruggedness, and robustness.

Project: MM19


analyzer

an instrument and/or specimen processing and handling device that performs measurements on patient specimens of quantitative, clinically relevant analytes

Project: POCT04, AUTO01, AUTO02

NOTE: A portion of a patient's specimen is consumed in the analytic process.


anatomy

study of the structure of an organism

Project: GP48

NOTE: In humans, anatomy is the study of structure and function of the body.


ancillary

a secondary or subsidiary action (eg, testing) or location (eg, site)

Project: POCT04


angle of insertion

the angle formed by the surface of the arm and the needle entering the arm.


angle of insertion

the angle formed by the surface of the skin and the needle entering the skin

Project: GP41


anion exchange resin

an ion-exchange resin with immobilized positively charged exchange sites, which can bind negatively charged ionized species.

Project: GP40


annealing

the hybridization of two complementary strands of nucleic acid, as in the hybridization of a probe or primer with the target DNA.

Project: MM01, MM10, MM02, MM09, MM12, MM22


anode

a positively charged conductor by which electrons leave an electrical device.

Project: GP28


anomalous result

result that is inconsistent to a clinically significant degree, with another result obtained from the same sample, with a result from another.

Project: EP07


ANSI

acronym for American National Standards Institute (www.ansi.org);

Project: AUTO01, AUTO02, POCT02, AUTO07, POCT01, AUTO03

NOTE: In Automation, the Microsoft Windows ANSI character set is composed of International Organization for Standardization (ISO) 8859/x plus additional characters.


antecubital

situated anterior to the cubitis, or elbow (Dorland's Illustrated Medical Dictionary. 32nd ed. Elsevier Saunders; 2012)

Project: GP41


antecubital fossa

area of the arm anterior and below the bend of the elbow where major veins for venipuncture are located

Project: GP48


anteroom

small room placed between two rooms or spaces that acts as an air lock or transition space between two areas of differential air pressure to reduce contaminated air from escaping one area and going into the other.

Project: QMS04


antianimal antibodies

antibodies that show strong avidity for test antibodies of one species, but the antibody may cross-react with immunoglobulins from other species.

Project: I/LA30


antibiogram

overall profile of antimicrobial susceptibility testing results of a microbial species to a battery of antimicrobial agents.

Project: M52, M38, M27, M44


antibiogram

for the purpose of CLSI document M39, see cumulative antimicrobial susceptibility test data summary.

Project: M39


antibody

specific immunoglobulin formed by B lymphocytes and plasma cells in response to exposure to an immunogenic substance and able to bind to the antigen.

Project: H56


antibody

a substance formed in the body in response to a foreign protein (an antigen) that interacts only with that substance; however, it may also bind to structurally related substances.

Project: I/LA30


antibody

specific immunoglobulin formed by B-lymphocytes in response to exposure to an immunogenic substance and able to bind to this (ISO 19001)

Project: ISO 19001, I/LA23

NOTE: The molecule of an immunogenic substance contains one or more parts with a characteristic chemical composition, an epitope (ISO 19001).


antibody

a specific immunoglobulin formed by B lymphocytes and plasma cells in response to exposure to an immunogenic substance and able to bind to this immunogenic substance (modified from ISO 19001)

Project: NBS06


antibody

any of numerous Y-shaped protein molecules produced by B-cells as a primary immune defense, each molecule and its clone having a unique binding site that can combine with the complementary site of an antigen, as on a virus or bacterium, thereby signaling other immune defenses; the functional portion of antiserum, often referred to collectively as a population of molecules, each member of which is capable of reacting with (binding to) a specific antigenic determinant

Project: I/LA20

NOTE 1: An antibody molecule is, by definition, monospecific, but it might also be idiospecific, heterospecific, polyspecific, or of unwanted specificity. It cannot be nonspecific, except in the sense of nonimmunochemical binding; NOTE 2: These proteins are immunoglobulins and bind by means of specific binding sites to a specific antigenic determinant.


antibody

the functional component of antiserum or hybridoma supernatant, composed of a population of Y-shaped protein molecules, each member of which is capable of reacting with (binding to) a specific antigenic determinant;

Project: I/LA28

NOTE: These antibodies are produced by B lymphocytes as a primary immune.


antibody

1) any of numerous Y-shaped protein molecules produced by B cells as an acquired primary immune defense following antigen exposure, each molecule having a unique binding site (either 2 for IgG, IgA, IgD, and IgE, or 10 for IgM) that can combine with the complementary site of an antigen thereby potentially signaling other immune defenses; 2) the functional component of antiserum, often referred to collectively as a population of molecules, each member of which is capable of reacting with (binding to) a specific antigenic determinant;

Project: NRSCL8, I/LA34

NOTE 1: An antibody molecule is, by definition, monospecific, but it might also be idiospecific, heterospecific, polyspecific, or of unwanted specificity. It cannot be nonspecific, except in the sense of nonimmunochemical binding; NOTE 2: These proteins are immunoglobulins and bind by means of specific binding sites to a specific antigenic determinant.


antibody

specific immunoglobulin formed by B lymphocytes in response to exposure to an immunogenic substance (antigen) and able to bind to this antigen;

Project: I/LA26

NOTE: The molecule of an immunogenic substance contains one or more parts with a characteristic chemical composition, ie, an epitope.


antibody binding capacity

(ABC) as used in this document, the number of antibody molecules specifically bound to the homologous antigen (receptor) in a cell or microparticle under saturating or near-saturating conditions;

Project: I/LA24

NOTE 1: Antibody binding capacity is often used as an indirect measure of expression of the homologous antigen, which is usually a cellular receptor or capture antibody on a microsphere. It is in this context that near-saturation binding is required. However, some results given in ABC units (such as titrations) clearly do not imply saturation; NOTE 2: "ABC" has become a general term that does not distinguish between binding capacities for native antibody and fluorochrome-antibody conjugates. It is even used mistakenly to describe the binding capacity for ligands other than antibodies. While terms like "ligand binding capacity," and "conjugate binding capacity" would be more precise, they are rarely used; NOTE 3: Some reports use the variant term "AB/C" to stand for "Antibodies Bound per Cell." This term presumably does not imply a requirement for saturation.


antibody identification

the testing of serum or plasma against a panel of different materials that express red blood cell (RBC) antigens to identify the antibody or antibodies.

Project: I/LA33


antibody screen

the testing of serum or plasma with material expressing RBC antigens for detection of unexpected antibodies.

Project: I/LA33


anticoagulant

agent that prevents the coagulation of blood.

Project: H21


anticoagulant

an agent that prevents coagulation of blood or blood products

Project: POL1/2, GP39, GP34, H56, POCT04


anticoagulant

an agent, natural or pharmacological, that inhibits clotting of blood or plasma.

Project: POCT14, H58, MM17, H59


anticoagulant

a substance that prevents coagulation, ie, it inhibits blood or plasma from clotting.

Project: H48, H60


antifatigue mats

padded mats that are placed on floors in areas where staff must stand for long periods of time.

Project: QMS04


antifungal agent

agent that destroys or resists fungus

Project: QMS04

NOTE: Antifungal agents are capable of destroying or inhibiting their growth.


antigen

in immunology, any substance that can stimulate the production of antibodies by an organism and combine specifically with them

Project: I/LA23, I/LA20, I/LA28, I/LA34

NOTE: This is the name of the measurand in immunohistochemistry assays.


antigen

any substance which, when injected into an animal or human being, elicits an immune response, either cellular, humoral, or both.

Project: I/LA26, I/LA29


antigen

any protein that, when introduced into the body, causes the development of antibodies.


antigen

any substance either foreign or native that elicits an immune response through recognition by receptors on the surface of immune cells.

Project: NBS06


antigen excess

the presence of an amount of antigen, in relationship to antibody concentration, that results in increased solubility of immune complexes, decreased apparent reactivity, and in underestimation of antigen quantity (Cf. DI1)

Project: DL01


antigen retrieval

the process of rendering a fixed and paraffin-embedded tissue accessible for binding by antibodies;

Project: I/LA28

NOTE: Typically, antigen retrieval follows deparaffinization; however, some methods combine the two steps into a single process. At the molecular level, antigen retrieval is the release of covalent cross-links that are most often the result of formalin fixation. Elements of additional deparaffinization and reduction to denatured protein are an element of antigen retrieval. Antigen retrieval is mediated typically by enzymatic methods (trypsin and proteinase K) or heat-based approaches with specific buffers (see heat-induced antigen retrieval and analytical interference). (Some authors prefer the term epitope retrieval.)


antigenic determinant

the minimum molecular structure of the antigenic site that will react with a monoclonal antibody.

Project: DI01, I/LA18


antigenicity

the capacity for a substance to react with appropriate antibodies in a suitable in vitro immunological assay, such as flocculation, immunogel diffusion, ELISA.


antigen-presenting cells

cells (primarily dendritic cells, monocytes, and B-cells) that are able to bind and internalize large protein antigens, process them, and then present peptide fragments of these antigens to cytotoxic T-cells and T-helper cells in the context of their major histocompatibility complex Class I and Class II surface molecules, respectively.

Project: I/LA26


antiglobulin

an antibody produced by an animal in reaction to the introduction of globulin from another animal (RHUD1.7CD).

Project: I/LA23


antiglycolytic agent

agent that inhibits the utilization of glucose by blood cells.

Project: GP39


antihuman globulin (AHG)

an antibody directed against human immunoglobulin and/or complement;

Project: I/LA33

NOTE: It is used to perform the antihuman globulin test (previously known as Coombs test). The preparation may be either polyspecific (anti-IgG plus anticomplement) or monospecific (anti-IgG or anticomplement).


antihuman globulin phase

testing step where the use of a secondary antibody, typically directed against human immunoglobulin G (IgG) or C3 molecules, detects bound IgG or C3 on red blood cells (patient, donor, or reagent); the secondary antibody binds to the cell-bound IgG or C3 that has attached to the red cell either in vivo or in vitro.

Project: ILA33


antimatrix

antibody directed against the solid phase support (ie, microparticles, plastic in enzyme-linked immunosorbent assay [ELISA] plates) that may interfere with the test system by causing high background levels.

Project: I/LA29


antimicrobial agent

substance of biological, semisynthetic, or synthetic origin that inhibits the growth of or kills bacteria, and is thus of potential use in the treatment of infections (ISO 20776-1)

Project: ISO 20776-1

NOTE: Disinfectants, antiseptics, and preservatives are not included in this definition (ISO 20776-1).


antimicrobial agent

agent that destroys or resists microorganisms

Project: QMS04

NOTE: Antimicrobials are capable of destroying or inhibiting the growth of microorganisms.


antimicrobial resistance surveillance

the continuous, intensive, targeted, and nonrandom collection of data on the incidence, prevalence, and spread of antimicrobial resistant bacteria and antimicrobial resistance genes.

Project: VET05


antimicrobial susceptibility test device

(AST device) device including all specified components used to obtain test results that allow susceptible, intermediate, and resistant (SIR) categorization of bacteria with specific antimicrobial agents (ISO 20776-2)

Project: ISO 20776-2

NOTE: Specific components include inoculators, disposables and reagents, media, disks, and readers. Nonspecific components, such as swabs, pipettes, and tubes, are not part of the device (ISO 20776-2).


antimicrobial susceptibility test interpretive category

1) classification based on a bacterium's in vitro response to an antimicrobial agent relative to that agent's serum concentration (or other relevant fluid concentration) that is attainable using standard of practice dose or the labeled target animal species for that type of infection and infecting organism; 2) susceptible antimicrobial susceptibility test interpretive category - a category that implies that an infection due to the isolate may be appropriately treated with the dosage regimen of an antimicrobial agent recommended for that type of infection and infecting species, unless otherwise indicated; 3) intermediate antimicrobial susceptibility test interpretive category - a category that implies that an infection due to the isolate may be appropriately treated in body sites where the drugs are physiologically concentrated or when a high dosage of drug can be used; also indicates a "buffer zone" that should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations; 4) resistant antimicrobial susceptibility test interpretive category - resistant isolates are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules and/or fall in the range where specific microbial resistance mechanisms are likely (e.g., beta-lactamases), and clinical efficacy has not been reliable in treatment studies.

Project: VET02, VET03


antimicrobial susceptibility test interpretive category

a classification based on an in vitro response of an organism to an antimicrobial agent at levels corresponding to blood or tissue levels attainable with usually prescribed doses of that agent;

Project: M27, M44

NOTE 1: For mycobacteria two different categories, "critical concentration" and "minimum inhibitory concentration" have been used to categorize the in vitro results; NOTE 2: For members of the MTBC, when tested against the lower concentration of some agents, the "critical concentration" category is applied. Testing of an additional higher concentration may also be recommended for some agents. However, there is no "intermediate" interpretive category when the "critical concentration" category is applied, even when testing is performed both at the critical concentration and the additional higher concentration; NOTE 3: For NTM and for the aerobic actinomycetes, only the "minimum inhibitory concentration" category is applied.


antimicrobial susceptibility test interpretive category

a classification based on an in vitro response of an organism to an antimicrobial agent;

Project: M24

NOTE 1: For mycobacteria, two different categories, "critical concentration" and "minimum inhibitory concentration," have been used to categorize the in vitro results; NOTE 2: For members of the MTBC, when tested against the lower concentration of some agents, the "critical concentration" category is applied. Testing of an additional higher concentration may also be recommended for some agents. However, there is no "intermediate" interpretive category when the "critical concentration" category is applied, even when testing is performed both at the critical concentration and the additional higher concentration; NOTE 3: For NTM and for the aerobic actinomycetes, only the "minimum inhibitory concentration" category is applied; NOTE 4: Determination of value considers multiple factors including pharmacokinetic and pharmacodynamic properties, concentrations of the agent corresponding to blood, tissue, or other body fluid levels attainable with usually prescribed doses of that agent, distribution of MIC values for clinical isolates, and, whenever possible, relation to clinical efficacy.


antimicrobial susceptibility test interpretive category

a classification based on an in vitro response of an organism to an antimicrobial agent at levels corresponding to blood or tissue levels attainable with usually prescribed doses of that agent; 1) susceptible – a category that implies that isolates are inhibited by the usually achievable concentrations of antimicrobial agent when the dosage recommended to treat the site of infection is used, resulting in likely clinical efficacy; 2) intermediate – a category that includes isolates with antimicrobial agent minimal inhibitory concentrations (MICs) that approach usually attainable blood and tissue levels and for which response rates may be lower than for susceptible isolates; NOTE: The intermediate category implies clinical efficacy in body sites where the drugs are physiologically concentrated (eg, quinolones and β-lactams in urine) or when a higher than normal dosage of a drug can be used (eg, β-lactams). This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations, especially for drugs with narrow pharmacotoxicity margins; 3) resistant – a category that implies that isolates are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules and/or that demonstrate zone diameters that fall in the range in which specific microbial resistance mechanisms (eg, β-lactamases) are likely, and clinical efficacy of the agent against the isolate has not been reliably shown in treatment studies; 4) nonsusceptible – a category used for isolates for which only a susceptible interpretive criterion has been designated because of the absence or rare occurrence of resistant strains. Isolates for which the antimicrobial agent MICs are above or zone diameters below the value indicated for the susceptible breakpoint should be reported as nonsusceptible; NOTE 1: An isolate that is interpreted as nonsusceptible does not necessarily mean that the isolate has a resistance mechanism. It is possible that isolates with MICs above the susceptible breakpoint that lack resistance mechanisms may be encountered within the wild-type distribution subsequent to the time the susceptible-only breakpoint is set; NOTE 2: For strains yielding results in the “nonsusceptible” category, organism identification and antimicrobial susceptibility test results should be confirmed.

Project: M45, M11


antimicrobial susceptibility test interpretive category

a classification based on an in vitro response of an organism to an antimicrobial agent at levels corresponding to blood or tissue levels attainable with usually prescribed doses of that agent

1) susceptible (S) – a category that implies that isolates are inhibited by the usually achievable concentrations of antimicrobial agent when the dosage recommended to treat the site of infection is used, resulting in likely clinical efficacy.

2) intermediate (I)a category that includes isolates with antimicrobial agent MICs that approach usually attainable blood and tissue levels and for which response rates may be lower than for susceptible isolates; NOTE: The intermediate category implies clinical efficacy in body sites where the drugs are physiologically concentrated (eg, quinolones and β‑lactams in urine) or when a higher than normal dosage of a drug can be used (eg, β‑lactams). This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations, especially for drugs with narrow pharmacotoxicity margins.

3) susceptible dose dependent (SDD) – a category that implies that susceptibility of an isolate is dependent on the dosing regimen that is used in the patient. In order to achieve levels that are likely to be clinically effective against isolates for which the susceptibility testing results (either minimal inhibitory concentrations [MICs] or disk diffusion) are in the SDD category, it is necessary to use a dosing regimen (ie, higher doses, more frequent doses, or both) that results in higher drug exposure than the dose that was used to establish the susceptible breakpoint. Consideration should be given to the maximum approved dosage regimen, because higher exposure gives the highest probability of adequate coverage of an SDD isolate. The dosing regimens used to set the SDD interpretive criterion are provided in Appendix E in CLSI document M100. The drug label should be consulted for recommended doses and adjustment for organ function; NOTE: The SDD interpretation is a new category for antibacterial susceptibility testing, although it has been previously applied for interpretation of antifungal susceptibility test results (see CLSI document M27-S4, the supplement to CLSI document M27). The concept of SDD has been included within the intermediate category definition for antimicrobial agents. However, this is often overlooked or not understood by clinicians and microbiologists when an intermediate result is reported. The SDD category may be assigned when doses well above those used to calculate the susceptible breakpoint are approved and used clinically, and where sufficient data to justify the designation exist and have been reviewed. When the intermediate category is used, its definition remains unchanged.

4) nonsusceptible (NS)a category used for isolates for which only a susceptible interpretive criterion has been designated because of the absence or rare occurrence of resistant strains. Isolates for which the antimicrobial agent MICs are above or zone diameters below the value indicated for the susceptible breakpoint should be reported as nonsusceptible; NOTE 1: An isolate that is interpreted as nonsusceptible does not necessarily mean that the isolate has a resistance mechanism. It is possible that isolates with MICs above the susceptible breakpoint that lack resistance mechanisms may be encountered within the wild-type distribution subsequent to the time the susceptible-only breakpoint is set; NOTE 2: For strains yielding results in the “nonsusceptible” category, organism identification and antimicrobial susceptibility test results should be confirmed (see Appendix A in CLSI document M100).

5) resistant (R)a category that implies that isolates are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules and/or that demonstrate zone diameters or MICs that fall in the range in which specific microbial resistance mechanisms (eg, β-lactamases) are likely, and clinical efficacy of the agent against the isolate has not been reliably shown in treatment studies.

Project: M23


antimicrobial susceptibility test interpretive category

a classification based on an in vitro response of an organism to an antimicrobial agent at levels corresponding to blood or tissue levels attainable with usually prescribed doses of that agent; 1) susceptible (S) – a category that implies that isolates are inhibited by the usually achievable concentrations of antimicrobial agent when the dosage recommended to treat the site of infection is used, resulting in likely clinical efficacy; 2) susceptible-dose dependent (SDD) – a category that implies that susceptibility of an isolate is dependent on the dosing regimen that is used in the patient. In order to achieve levels that are likely to be clinically effective against isolates for which the susceptibility testing results (either minimal inhibitory concentrations [MICs] or disk diffusion) are in the SDD category, it is necessary to use a dosing regimen (ie, higher doses, more frequent doses, or both) that results in higher drug exposure than the dose that was used to establish the susceptible breakpoint. Consideration should be given to the maximum approved dosage regimen, because higher exposure gives the highest probability of adequate coverage of an SDD isolate. The dosing regimens used to set the SDD interpretive criterion are provided in Appendix E in CLSI document M100. The drug label should be consulted for recommended doses and adjustment for organ function; NOTE: The SDD interpretation is a new category for antibacterial susceptibility testing, although it has been previously applied for interpretation of antifungal susceptibility test results. The concept of SDD has been included within the intermediate category definition for antimicrobial agents. However, this is often overlooked or not understood by clinicians and microbiologists when an intermediate result is reported. The SDD category may be assigned when doses well above those used to calculate the susceptible breakpoint are approved and used clinically, and where sufficient data to justify the designation exist and have been reviewed. When the intermediate category is used, its definition remains unchanged; 3) intermediate (I) – a category that includes isolates with antimicrobial agent MICs that approach usually attainable blood and tissue levels and for which response rates may be lower than for susceptible isolates; NOTE: The intermediate category implies clinical efficacy in body sites where the drugs are physiologically concentrated (eg, quinolones and β-lactams in urine) or when a higher than normal dosage of a drug can be used (eg, β-lactams). This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations, especially for drugs with narrow pharmacotoxicity margins; 4) resistant (R) – a category that implies that isolates are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules and/or that demonstrate zone diameters (M02) or MICs (M07) that fall in the range in which specific microbial resistance mechanisms (eg, β-lactamases) are likely, and clinical efficacy of the agent against the isolate has not been reliably shown in treatment studies; 5) nonsusceptible (NS) – a category used for isolates for which only a susceptible interpretive criterion has been designated because of the absence or rare occurrence of resistant strains. Isolates for which the antimicrobial agent MICs are above or zone diameters below the value indicated for the susceptible breakpoint should be reported as nonsusceptible; NOTE 1: An isolate that is interpreted as nonsusceptible does not necessarily mean that the isolate has a resistance mechanism. It is possible that isolates with MICs above the susceptible breakpoint that lack resistance mechanisms may be encountered within the wild-type distribution subsequent to the time the susceptible-only breakpoint is set; NOTE 2: For strains yielding results in the “nonsusceptible” category, organism identification and antimicrobial susceptibility test results should be confirmed.

Project: M02, M07


antimicrobial susceptibility test interpretive category

a classification based on an in vitro response of an organism to an antimicrobial agent at levels corresponding to blood or tissue levels attainable with usually prescribed doses of that agent. 1) susceptible - a category that implies that isolates are inhibited by the usually achievable concentrations of antimicrobial agent when the dosage recommended to treat the site of infection is used; 2) intermediate - a category that includes isolates with antimicrobial agent minimal inhibitory concentrations that approach usually attainable blood and tissue levels and for which response rates may be lower than for susceptible isolates. The intermediate category implies clinical efficacy in body sites where the drugs are physiologically concentrated (eg, quinolones and β-lactams in urine) or when a higher than normal dosage of a drug can be used (eg, β-lactams). This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations, especially for drugs with narrow pharmacotoxicity margins; 3) resistant - a category that implies that isolates are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules and/or that demonstrate minimal inhibitory concentrations that fall in the range in which specific microbial resistance mechanisms (eg, β-lactamases) are likely, and clinical efficacy of the agent against the isolate has not been reliably shown in treatment studies.

Project: M43


antimicrobial susceptibility test interpretive category

a classification based on an in vitro response of an organism to an antimicrobial agent at levels corresponding to blood or tissue levels attainable with usually prescribed doses of that agent; 1) susceptible – the “susceptible” category implies that isolates are inhibited by the usually achievable concentrations of antimicrobial agent when the dosage recommended to treat the site of infection is used; 2) susceptible-dose dependent (SDD) – the “susceptible-dose dependent” category implies that susceptibility of an isolate is dependent on the dosing regimen that is used in the patient. In order to achieve levels that are likely to be clinically effective against isolates for which the susceptibility testing results (either minimal inhibitory concentrations [MICs] or disk diffusion) are in the SDD category, it is necessary to use a dosing regimen (ie, higher doses, more frequent doses, or both) that results in higher drug exposure than the dose that was used to establish the susceptible breakpoint. Consideration should be given to the maximum approved dosage regimen, because higher exposure gives the highest probability of adequate coverage of an SDD isolate. The dosing regimens used to set the SDD interpretive criterion are provided in Appendix E of CLSI document M100. The drug label should be consulted for recommended doses and adjustment for organ function; 3) intermediate – the “intermediate” category includes isolates with antimicrobial agent MICs that approach usually attainable blood and tissue levels, and for which response rates may be lower than for susceptible isolates. The intermediate category implies clinical efficacy in body sites where the drugs are physiologically concentrated (eg, quinolones and β-lactams in urine) or when a higher than normal dosage of a drug can be used (eg, β-lactams). This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations, especially for drugs with narrow pharmacotoxicity margins; 4) resistant – the “resistant” category implies that isolates are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules, and/or that demonstrate MICs or zone diameters that fall in the range where specific microbial resistance mechanisms (eg, β-lactamases) are likely, and clinical efficacy of the agent against the isolate has not been reliably shown in treatment studies; 5) nonsusceptible – a category used for isolates for which only a susceptible interpretive criterion has been designated because of the absence or rare occurrence of resistant strains. Isolates for which the antimicrobial agent MICs are above or zone diameters below the value indicated for the susceptible breakpoint should be reported as nonsusceptible; NOTE 1: An isolate that is interpreted as nonsusceptible does not necessarily mean that the isolate has a resistance mechanism. It is possible that isolates with MICs above the susceptible breakpoint that lack resistance mechanisms may be encountered within the wild-type distribution subsequent to the time the susceptible-only breakpoint is set; NOTE 2: For strains yielding results in the “nonsusceptible” category, organism identification and antimicrobial susceptibility test results should be confirmed.

Project: M39

NOTE: The SDD interpretation is a new category for antibacterial susceptibility testing, although it has been previously applied for interpretation of antifungal susceptibility test results (see CLSI document M27-S4). The concept of SDD has been included within the intermediate category definition for antibacterials. However, this is often overlooked or not understood by clinicians and microbiologists when an intermediate result is reported. The SDD category may be assigned when doses well above those used to calculate the susceptible breakpoint are approved and used clinically, and where sufficient data to justify the designation exist and have been reviewed. When the intermediate category is used, its definition remains unchanged.


antimicrobial susceptibility test interpretive category

classification of projected clinical outcome of treatment based on the causative microorganism’s in vitro response to an antimicrobial agent relative to the exposure to that agent, which is attainable using the labeled dose regimen for the target animal species for that type of infection and infecting organism.

Project: VET05


antinuclear antibodies

as used in this guideline, immunoglobulins detected by immunochemical staining of cells that bind specifically to cell nuclei or certain antigens in the cytoplasm, and immunoglobulins that bind specifically to certain purified nuclear or cytoplasmic antigens detected by binding reactions in gel precipitation assays, ELISA, and other assay methods such as protein microarrays.

Project: I/LA02


antisense strand

strand of DNA complementary to the sense strand.


antisepsis

method for avoiding infection in a wound or during a clinical procedure by the use of a chemical agent such as an antiseptic (ISO 15190)

Project: ISO 15190


antiseptic

chemical germicide formulated to be used on skin or tissue (ISO 15190)

Project: ISO 15190, M29, I17

NOTE 1: Antiseptics should not be used as disinfectants; NOTE 2: The US Food and Drug Administration has regulatory authority over antiseptic compounds.


antiseptic

a substance that inhibits the growth and development of microorganisms without necessarily killing them.

Project: M47


antiserum

a serum produced in various species of animals or human beings that contains antibodies to one or more antigens of interest.

Project: I/LA28


antiserum

a serum produced in animals or human beings that contains antibodies to one or more antigens of interest (I/LA18).

Project: ILA18


antithrombin

AT (formerly Antithrombin III) - a plasma protein which, when activated by heparin or heparin-like molecules containing a specific pentasaccharide sequence such as glucosaminoglycans on endothelial cells, is a potent, irreversible inhibitor of activated, procoagulant serine proteases such as thrombin and Factor Xa

Project: POCT14


antiviral resistance

a decrease in susceptibility to an antiviral drug that can be clearly established by in vitro testing and can be confirmed by genetic analysis of the virus and biochemical study of the altered enzymes;

Project: M33

NOTE 1: In vitro drug resistance must be distinguished from treatment failure in which the viral infection fails to respond to therapy. This failure may or may not be due to the presence of a drug-resistant virus, but may be related to the pharmacokinetics of the drug in an individual patient and the patient’s immunologic status; NOTE 2: For HSV, in vitro resistance to antiviral agents such as acyclovir and foscarnet has been correlated with clinical resistance.


antivitamin K plasma

plasma from an individual on antivitamin K (AVK) therapy

Project: H54


apheresis

the withdrawal of whole blood from the body, separation of one or more components, and return of remaining blood to the donor by transfusion

Project: QMS04


apolipoprotein

the lipid-free protein moiety of a lipoprotein;

NOTE: Several different apolipoproteins have been identified that differ in structure, function, and genetic control.


apoptosis

the process of programmed cell death resulting from specific cell signaling events.

Project: I/LA26


application

the purpose and context in which a sequencing technology is applied including features such as clinical indication, nucleic acid template structure, specified technical characteristics, and specimen types.

Project: MM09


appraisal costs

costs associated with measuring, evaluating, or auditing products or services to assure conformance to quality standards and performance requirements.

Project: QMS20


arbitrator

a qualified examiner, frequently with additional expertise and experience, who will resolve disagreements between the results of two qualified morphologist examiners.

Project: H20


arcing

electrical conduction through a gas in an applied electric field.

Project: GP28


area under the curve

(area under the receiver operating characteristic [ROC] curve) as applied to ROC curves, the area subtended by the ROC curve and bounded by the x-axis (false-positive fraction) and the y-axis (true-positive fraction) (I/LA21);

Project: ILA21

NOTE 1: By convention, the total area in ROC space is exactly 1 unit. A completely noninformative ROC curve will divide the total ROC space into two equal triangular areas of 0.5 units each. The AUC of an informative ROC must therefore be > 0.5 area units. A test with perfect discrimination would have an AUC of 1.0 area units (I/LA21); NOTE 2: The AUC is mathematically related or equivalent to certain statistical parameters, particularly the Mann-Whitney U (I/LA21); NOTE 3: Various mathematical approaches to calculating the AUC are available. The simplest is the trapezoidal approximation. More formal parametric and nonparametric approaches can be used (see CLSI document GP10); NOTE 4: The AUC is a good measure of the overall accuracy of a test but does not distinguish between sensitivity and specificity (I/LA21).


Arrhenius equation

a mathematical function that describes the approximate relationship between the rate constant of a chemical reaction and the reaction temperature and energy of activation.

Project: EP25


arterial oxygen tension-inspired oxygen fraction ratio

[PO2(aB)/FIO2//PaO2/FIO2] - the ratio of the partial pressure of oxygen in arterial blood to the fraction of inspired oxygen.

Project: NRSCL8


arterial puncture

the procedures for collecting a blood sample from an artery

Project: POCT04

NOTE: This blood is called "arterial blood."


arterial-alveolar oxygen tension ratio

[PO2(aB)/PO2 (A)//PaO2/PAO2//a/A ratio] ratio of the partial pressure of oxygen in arterial blood to the partial pressure of oxygen in alveolar gas. (Cf. C12, C25).

Project: C12, C25


arthrocentesis

aspiration of a joint.

Project: H56


arthrocentesis fluid

joint fluid obtained from aspiration of a joint.

Project: H56


artifact

arbitrarily defined measurand used as the origin in a metrological traceability chain.

Project: C53


artifact

an inaccurate observation, effect, or result, especially one resulting from the technology used in scientific investigation or from experimental error.

Project: MM09


ascitic fluid

serous fluid from the peritoneal cavity;

Project: I/LA18

NOTE: Monoclonal antibodies are commonly raised in vivo by implantation of hybridomas in the peritoneal cavity of mice, followed by purification of the antibodies from the resulting ascitic fluid.


aseptic

environmental conditions which minimize microbial contamination.

Project: C37


assay

as used in CLSI document I/LA28, the technical element of the immunohistochemical assay, exclusive of interpretation or reporting (see test.)

Project: I/LA28


assay

1) a quantitative determination or measurement of the amount, activity, or potency of a constituent or characteristic; 2) competitive binding assay - assay based on the competition of labeled and unlabeled analytes for a receptor (Cf. DI1); 3) assay - to analyze or measure a sample of a specimen to determine the amount, activity, or potency of a specific analyte or substance; 4) qualitative assay - reports only the presence or absence of the analyte, without quantitation;

Project: DI01, I/LA18, I/LA23, ILA33

NOTE 1: A positive test result implies only that the assay signal exceeds the analytical threshold (detection limit), or a cutoff point set to give an arbitrary combination of sensitivity and specificity; NOTE 2: In simplistic and idealistic terms, detection of the analyte should correlate with the presence (and nondetection with the absence) of the infectious agent or of related antibodies, resulting from either natural exposure or immunization; 5) quantitative assay - generates a spectrum of signal responses that correlate with the concentration of the analyte of interest; NOTE 3: If the analyte preparations with known concentrations are available for calibration, the actual concentration of the analyte can be determined; 6) semiquantitative assay - essentially a qualitative assay with an additional option for the response range (degree of positivity, dilution to which positive results are obtained, or comparison to a color chart); NOTE 4: For the purpose of this document, assay is also known as the measurement procedure (see the definition in this section);


assay

see measurement procedure.

Project: EP05


assay

a quantitative determination or measurement of the amount, activity, or potency of a constituent or characteristic;

Project: MM22

NOTE 1: A qualitative assay reports only the presence or absence of the analyte, without quantification; NOTE 2: A positive test result implies only that the assay signal exceeds the analytical threshold (detection limit), or a cutoff point set to give an arbitrary combination of sensitivity and specificity; NOTE 3: For the purpose of MM22, assay is also known as the measurement procedure.


assay intended use population

a group of subjects intended to be tested by the assay in question (eg, with genotypes and phenotypes representative of the population) (MM17).

Project: MM17


assay range

the upper and lower limits of the amount, activity, or potency of a specific analyte between which measurement is possible.

Project: NRSCL8


assay sensitivity

See sensitivity.

Project: ILA29


assay value

the amount, activity, or potency of an analyte as determined by analysis.

Project: NRSCL8


assayed value

a value that has been determined by analysis.


assembly

the tube and the closure.

Project: GP39


assessment

systematic process of collecting and analyzing data to determine the current, historical, or projected status of an organization, person, or project.

Project: QMS06, GP26, QMS14


assessment

systematic process of collecting and analyzing data to determine the current, historical, or projected condition of an organization, process, or activity

Project: QMS16, QMS21, QMS03, QMS15, QMS20

NOTE: Also referred to as inspection and survey.


assessment event

a test assessment procedure(s) performed at one point in time.


assessor

representative of the assessment organization who determines whether the laboratory meets the assessment organization’s requirements

Project: QMS17

NOTE: An assessor may also be referred to as an inspector, auditor, surveyor, or investigator.


asset

any resource both available and useful during disaster response.

Project: GP36


assigned value

value attributed to a particular property of a proficiency test item (ISO 13528)

Project: QMS24


assigned value

a value that has been given to a material and is to be used as the acceptable or desired value for an analyte.


assisted monitoring of blood glucose

an instance in which the testing procedure is performed by a health care provider for an individual or individuals

Project: POCT04


ASTM International

the official name of the organization formerly known as the American Society for Testing and Materials;

Project: AUTO01, AUTO02, AUTO07, AUTO03

NOTE: ASTM International has developed various high- and low-level communications protocols.


ataxia

a neurological sign and symptom consisting of gross lack of coordination of muscle movements. Ataxia is a nonspecific clinical manifestation implying dysfunction of parts of the nervous system that coordinate movement, such as the cerebellum;

Project: MM19

NOTE: Several possible causes exist for these patterns of neurological dysfunction.


atomic mass unit

(amu) 1/12th of the atomic mass of 12C (carbon-12)

Project: NBS04

NOTE: Although there is currently no International System of Units term or symbol for “daltons,” both the terms and symbols “atomic mass unit” and “(amu)” and “dalton” and “(Da)” are equally valid in mass spectrometry.


atopy

the inherited tendency to develop immediate-type hypersensitivity to common and generally harmless substances and/or develop atopic diseases (eg, allergic rhinoconjuncitivitis, allergic asthma, atopic eczema, and immunoglobulin E [IgE]−mediated food allergies)

Project: I/LA20

NOTE: A predisposition for atopy (atopic status) can be identified by demonstrating sensitization (IgE antibody positivity).


atopy

the inherited tendency to develop immediate-type hypersensitivity to common and generally harmless substances.

Project: ILA34


attestation

the responsibility of the individual testing or examining the samples and the laboratory director to testify to the routine integration of the samples into the patient workload using the laboratory’s routine methods (42 CFR 1236).

Project: MM14


atypical

a term used by pathologists to describe cells or tissues having some or all of the morphologic characteristics associated with malignancy.

Project: MM02


AUC

the area under the concentration-time curve. For regimens associated with dosing intervals of 24 hours or less, AUC represents steady state blood levels estimated over a 24-hour dosing interval (AUC 24) (where blood concentrations indicate measurement in either plasma or serum). For once daily or more frequent dosing, AUC 24 is equal to AUC 0-∞ estimated following a single dose if the pharmacokinetics are dose-proportional. With alternative dosing regimens or when steady state blood levels are not achieved (eg, every-other-day dosing for two sequential doses or one single dose for the entire period of therapy), the AUC may need to be defined by a partial area (eg, AUC from hour zero to 24 for a single dose therapy). AUC values should be adjusted to reflect unbound (free) drug concentrations in serum or plasma. Other approaches using total drug concentrations may be considered if scientifically justified.

Project: VET02


AUC/MIC

(ratio) for drugs with dosing frequencies of every 24 hours or less, this is calculated as the area under the concentration-time curve over 24 hours (AUC24) in steady state divided by the MIC. For drugs with longer than a 24-hour dosing interval (including products intended for single administrations), the clinical relevance of AUC/MIC values has not been fully established. Therefore, for these other dosing regimens, an alternative metric should be defined.

Project: VET02


audit

systematic, independent, and documented process for obtaining objective evidence and evaluating it objectively to determine the extent to which the audit criteria are fulfilled (ISO 9000)

Project: QMS16, QMS21, ISO 9000, QMS17, QMS06, QMS12, QMS01, QMS14, QMS15, QMS20


audit conclusion

outcome of an audit, after consideration of the audit objectives and all audit findings (ISO 9000)

Project: QMS15


audit criteria

set of policies, procedures, or requirements used as a reference against which objective evidence is compared (ISO 9000)

Project: QMS15


audit evidence

records, statements of fact, or other information which are relevant to the audit criteria and verifiable (ISO 9000)

Project: QMS15


audit findings

results of the evaluation of the collected audit evidence against audit criteria (ISO 9000)

Project: QMS15


audit plan

description of the activities and arrangements for an audit (ISO 9000)

Project: QMS15


audit program

set of one or more audits planned for a specific time frame and directed towards a specific purpose (ISO 9000)

Project: QMS15


audit sample testing

testing of stored aliquots from a biological sample repeatedly over time in a specific assay system

Project: QMS24


audit scope

extent and boundaries of an audit (ISO 9000)

Project: QMS15


audit team

one or more auditors conducting an audit, supported if needed by technical experts (ISO 9000)

Project: QMS15


audit trail

1) data in the form of a logical path linking a sequence of events, used to trace the transactions that have affected the contents of a record; 2) a chronological record of system activities that is sufficient to enable the reconstruction, reviews, and examination of the sequence of environments and activities surrounding or leading to each event in the path of a transaction from its inception to output of final results (ISO/IEC International Standard 812)

Project: AUTO08


audit trail

an electronic log of transactions, detailing all events that have occurred in the laboratory automation system, including date and time of these events, which operator was responsible or directs processes, and any additional details.

Project: AUTO01, AUTO02, AUTO03


auditee

organization (or function) being audited (modified from ISO 9000)

Project: QMS15


auditor

person who conducts an audit (ISO 9000)

Project: QMS15


audit-sample testing

testing of stored aliquots from a biologic sample repeatedly over time in a specific assay system.


authentication

process of determining that an entity (someone or something) is the one claimed to be.


authentication

the process of verifying the identity of a user, process, or device, often as a prerequisite to allowing access to resources in an information system;

Project: AUTO11

NOTE: This process is usually achieved by supplying the user ID and a unique password (what the user knows), security token (what the user has), or biometrics (who the user is).


authorization

recognition of a person who has satisfied the qualification requirements to perform point-of-care blood glucose testing within an institution.

Project: POCT12


authorization

In Automation and Informatics, process of granting rights or access to systems, applications, or networks;

NOTE: Authorization determines who is trusted for a given purpose.


authorization

recognition of a person who has satisfied the qualification requirements to perform point-of-care blood glucose testing within an institution.

Project: POCT13


authorization

the process of granting rights or access to systems, applications, or networks;

Project: AUTO11

NOTE: Authorization determines who is trusted for a given purpose.


authorized person

an individual authorized under state law to order tests or receive test results, or both (U.S. CFR 493 February 28, 1992).


authorized representative

any natural or legal person established within a country or jurisdiction who has received a mandate from the manufacturer to act on his behalf for specified tasks with regard to the latter's obligations under that country's or jurisdiction's legislation (ISO 18113-1)

Project: ISO 18112-1, ISO 18113-1, ISO 18113-2, ISO 18113-3

NOTE 1: In the European Union, Directive 98/79/EC [38] requires the manufacturer to designate an “EC authorized representative”, established in the European Community if the manufacturer is not located in the European Community (ISO 18113-1); NOTE 2: Adapted from Directive 98/79/EC of the European Parliament and the Council of 27 October 1998 on in vitro diagnostic medical devices, Official Journal of the European Union L331, December 7, 1998 (ISO 18113-1).


autoantibody

an antibody that an organism produces against any of its own tissues, cells, or cell components (RHUD1.7CD) (Cf. DI1).

Project: DL01


autochthonous

(autologous) derived from the subject itself (Cf. DI1).

Project: DI01


autochthonous

describes a microorganism that is indigenous to a specific environment.

Project: M56


autoclave

1) an apparatus in which steam under pressure effects sterilization (RHUD-1.7CD); 2) to sterilize using steam under pressure


autocontrol

where the serum or plasma and RBC from the same individual are combined and undergo the same test conditions as the serum and reagent panel cells.

Project: ILA33


autofluorescence

background fluorescence arising from intrinsic sources in unstained measurands (particularly cells) under conditions used to detect desired fluorochromes.

Project: I/LA24


autofluorescence

the intrinsic fluorescence of unstained cells, generally caused by pyrimidines and flavin nucleotides (H42);

Project: H43, H42, H52

NOTE 1: The level of autofluorescence is a function of the excitation wavelength and varies with the cell type analyzed and/or the state of cellular activation. Cultured cell lines, neutrophils, and macrophages usually demonstrate higher levels of autofluorescence with 488 nm excitation, and proportional lower autofluorescence with excitation at longer wavelengths (eg, 635 nm). Autofluorescence can be decreased by specific sample preparation procedures (eg, incubation with crystal violet); NOTE 2: The level of autofluorescence is a function of the excitation wavelength and varies with the cell type analyzed and/or the state of cellular activation. Cultured cell lines, neutrophils, and macrophages usually demonstrate higher levels of autofluorescence with 488 nm excitation, and proportional lower autofluorescence with excitation at longer wavelengths. Autofluorescence of RBCs is significantly lower than that of WBCs, and instrument settings may need to be adjusted accordingly.


autograft

a tissue grafted into a new position in and/or on the body of the person from whom it was removed (Cf. DI1).

Project: DI01


autoimmunization

the process of becoming immune against constituents of one’s own cells, tissue, or components thereof (Cf. DI1).

Project: DI01


automated

1) a characterization applied when all analytical processes, including sample and reagent uptake, sample/reagent interaction, chemical/biological analysis, result calculation, and result readout are mechanized; 2) an inclusive term to denote the instrument, reagents, and methods of the device under study;

Project: AUTO01, AUTO02, H20, AUTO03

NOTE: These are usually controlled by a set of stored, modifiable instructions (US CFR 493 February 28, 1992).


automated blood culture system

a blood culture system that uses mechanical systems to incubate, agitate, and/or monitor blood culture bottles for microbial growth.

Project: M47


automated instrument

a laboratory instrument that may or may not be connected to a laboratory information system (LIS), hospital information system (HIS), and/or laboratory automation system (LAS), which performs measurements on a patient's sample;

Project: AUTO01, AUTO02

NOTE: These instruments may have specific hardware and/or software modifications that allow interface to a laboratory automation system.


automated MIS

MIS in which all, or most, steps (eg, inoculation, incubation, result interpretation) are performed by an instrument.

Project: M50


automated skin puncture device

a single-use device that punctures or cuts the skin with a lancet or blade that automatically retracts into a protective housing; used for collecting a capillary blood specimen

Project: GP42


automated system

a system that may be fully automated or semiautomated.

Project: ILA33


automated system administration

software module that verifies accessibility and all aspects of security are controlled; pertains to management of the information infrastructure within the automated system;

Project: ILA33

NOTE: Management includes functions such as installation of software updates; configuration of test definitions, queries, reports, or new workstations; creation of user accounts (ie, assignment of user passwords and user access levels); inactivation of users; and completion of software preventive maintenance requirements such as system backups and monitoring and allocation of mass storage space.


automation system

a variety of possible systems that can include some of the following types: automated instruments, laboratory information systems (LIS), laboratory automation systems (LAS), hospital information systems (HIS), and front-end processing devices.

Project: AUTO01, AUTO02


automation system

any of a variety of possible hardware systems that can include one or more of the following types: automated analyzers, modular or task-targeted automated systems (eg, accessioning systems, aliquotters, storage systems), and total laboratory automation systems (eg, track systems that may connect and operate input-output units, automated analyzers, and other task-targeted devices such as aliquotters, centrifuges, and storage units). These automation systems may be operated by or have interfaces to hospital information systems, laboratory information systems, and laboratory automation systems. See laboratory automation system and laboratory information system for additional clarity.

Project: AUTO12


autonomy

the right to choose one’s own actions or course of life so long as doing so does not interfere unduly with the lives and actions of others

Project: GP45

NOTE: Autonomy is the basis of the ethical value of respect for persons and respect for the subjects in research studies, and forms the basis of requirements for informed consent, protection of vulnerable subjects, and maintaining confidentiality of research data.


autoradiography

the process by which a radioisotope (usually 32P or 35S) or chemiluminescent tag is located within a gel or on a sheet of nitrocellulose paper by placing photographic or x-ray film in contact (inside a dark “holder”) with the gel or paper and waiting for several hours or several days for “exposure” to occur;

Project: MM10

NOTE: When developed, the film will display an image of all the tagged molecules in the gel or on the nitrocellulose and thus pinpoint their locations and relative positions within the gel or on the nitrocellulose.


autosampler

mechanical device used to reliably and reproducibly introduce accurately known volumes of specimen extracts into a flow stream for analysis

Project: NBS04

NOTE: In NBS04, the analysis is by tandem mass spectrometry.


autoverification

(automated result verification) the automated actions performed by a computer system related to the release of test results to the medical record using criteria and logic established, documented, and tested by the medical staff of the laboratory

Project: EP33, AUTO10

NOTE: The criteria can be simple or complex and involve many different parameters. The system offers the highest levels of consistency and the ability to handle complex algorithms in a very efficient way.


average affinity constant

the average affinity constant of a population of antibody molecules;

Project: NRSCL8

NOTE: The average or mean affinity constants are usually described for polyclonal antisera because of their heterogeneity (Cf. I/LA18, LA1, DI1).


avidity

the net affinity of all binding sites of all antibodies in the antiserum, under specified physicochemical reaction conditions;

Project: NRSCL8, ILA23, ILA29

NOTE: It is a function of the affinities of the antibody-combining sites on all antibodies present in an antiserum and all of the antigenic determinants of available macromolecules (I/LA15).


avidity

a measure of strength of bi- or multivalent antigen/antibody interaction.

Project: I/LA28


avidity

net affinity of all binding sites of antibodies.

Project: ILA30


avidity

the combined intensity of attraction of all antigenic sites on an antigen molecule and all antibodies to those sites;

NOTE: Avidity depends on the antibody isotype (valence), the size and conformation of the antigen molecules, and the number of antigenic epitopes.


AVK plasma

See antivitamin K plasma.

Project: H54


azeotrope

a blend of two or more components with equilibrium vapor phase and liquid phase compositions that are the same at a given temperature and pressure

Project: GP40


azoospermia

the medical condition of a male not having any measurable level of sperm in his semen. It is associated with very low levels of fertility.

Project: MM19


backdraft

exhaust vents located at the back of the countertop, designed to take chemical fumes that are heavier than air out of a space

Project: QMS04


backsplash

small strip placed on top of a countertop, at the back, to protect the wall

Project: QMS04


bacteremia

the presence of bacteria in the bloodstream;

Project: M47

NOTE: Bacteria isolated from blood may be the cause of sepsis, indeterminate as a cause of sepsis, or contaminants.


bactericide

a chemical or physical agent that kills bacteria

Project: GP40


badge

familiar, externally visible identification device;

Project: GP36

NOTE: Badges may also be generated by emergency agencies during an incident, and may bear expiration dates and specific access restrictions.


balanced

describes an experimental design or dataset wherein all cells (“treatment combinations”) have the same number of observations. A design or dataset is unbalanced if this condition fails to hold;

Project: EP05

NOTE: In concrete terms, for precision studies of the kind discussed in Chapters 3 and 4 of EP05, the experimental design is balanced if, for any given sample, it specifies the same number of replicates for each run; the same number of runs for each day; and, for a multisite study, the same number of days for each site. Otherwise, the design is unbalanced. (Note that all designs recommended in EP05 are balanced.) The corresponding dataset is balanced if it has the same number of results for each run, day, and site—ie, if the design is balanced and no results are missing or omitted from the analysis. Otherwise, the dataset is unbalanced.


balanced heparin

a heparin preparation in which sodium, potassium, and calcium are present in normal blood concentrations, and which may be used to anticoagulate blood to be used in the subsequent measurement of these ions with minimal influence on true values.


balanced scorecard

development and use of interrelated and strategic performance measures (metrics) throughout the organization that cover perspectives that include finances, customer requirements, internal business, and innovation and learning.

Project: GP35


bar code

1) an array of parallel rectangular bars and spaces that creates a symbology representing a number or alphanumeric identifier; 2) an array of rectangular lines and spaces that is arranged in a predetermined pattern following unambiguous rules and representing data that are referred to as characters (ASTM F1156);3) an identification code consisting of a pattern of vertical bars whose width and spacing identify the item marked;

Project: AUTO01, AUTO02, AUTO07, AUTO03, ILA33, AUTO12

NOTE: The code is meant to be read by an optical input device, such as a bar code scanner. Applications include retail product pricing labels, identification of library documents, and railroad boxcar identification (IEEE 610.2).


bar code

a short sequence of deoxynucleotides that can serve as a unique marker for tracking material from a given source through multiplex processing.

Project: MM09


bar length

the length of the bars in the bar code.

Project: AUTO01, AUTO02, AUTO07, AUTO12


base call

1) ability to distinguish presence of an adenosine (A), a thymidine (T), a cytidine (C), or a guanosine (G) at a given position within a sequence ladder or compilation of overlapping sequence ladders; 2) ability to distinguish presence of an adenine (A), a thymine (T), a cytosine (C), or a guanine (G) at a given position within a sequence or compilation of overlapping sequences;

Project: MM10, MM18

NOTE: Positions may be ambiguous and represented by an S (G or C), W (A or T), K (G or T), Y (C or T), M (A or C), R (A or C), R (A or G), B (C, G, or T), D (A, G, or T), H (A, C, or T), V (A, C, or G), or N (any base) (MM09). These designations were created by the International Union of Biochemistry (IUB) and are called IUB codes (MM18).


base call

ability to distinguish presence of an adenine (A), a thymine (T), a cytosine (C), or a guanine (G) at a given position within a sequence or compilation of overlapping sequences;

Project: MM09

NOTE: Positions may be ambiguous and represented by an S (G or C), W (A or T), K (G or T), Y (C or T), M (A or C), R (A or G), B (C, G, or T), D (A, G, or T), H (A, C, or T), V (A, C, or G), or N (any base).


base excess

the substance concentration of base, determined by titration with strong acid under specified conditions.

Project: NRSCL8


base excess of blood

the substance concentration of base determined by titration of blood with a strong acid or base to a pH of 7.40 with a pCO2 of 40 mmHg (5.3 kPa) at 37 ºC (C46);

Project: C46

NOTE: This can be determined by titration of blood with a strong acid or base to a plasma pH of 7.40 with PCO2 at 40 mmHg and at 37 ºC, but routinely is determined on the basis of a standardized equation found in CLSI/NCCLS document C12.


base excess of extracellular fluid

the {substance} concentration of base determined by titrating a model of extracellular fluid to a pH of 7.40 with a pCO2 of 40 mmHg (5.3 kPa) at 37 °C (C46);

Project: C46

NOTE 1: The model may be obtained by diluting one volume of blood with two volumes of its own plasma (IFCC/EPpH95); NOTE 2: This quantity cannot be determined directly, as can cBE(B), but it is determined in practice based on a standardized equation found in CLSI/NCCLS document C12 (Cf. C12, C25, C27).


base quantity

quantity in a conventionally chosen subset of a given system of quantities, where no subset quantity can be expressed in terms of the others (JCGM 200:2012)

Project: ISO IEC Guide 99

NOTE 1: The subset mentioned in the definition istermed the "set of base quantities." EXAMPLE: The set of base quantities in the International System of Quantities (ISQ) is given in 1.6 (JCGM 200:2012); NOTE 2: Base quantities are referred to as being mutually independent since a base quantity cannot be expressed as a product of powers of the other base quantities (JCGM 200:2012); NOTE 3: ‘Number of entities’ can be regarded as a base quantity in any system of quantities (JCGM 200:2012).


base unit

measurement unit that is adopted by conventionfor a base quantity (JCGM 200:2012)

Project: ISO IEC Guide 99

NOTE 1: In each coherent system of units, there is only one base unit for each base quantity. EXAMPLE: In the SI, the metre is the base unit of length. In the CGS systems, the centimetre is the base unit of length (JCGM 200:2012); NOTE 2: A base unit may also serve for a derived quantity of the same quantity dimension. EXAMPLE: Rainfall, when defined as areic volume (volume per area), has the metre as a coherent derived unit in the SI (JCGM 200:2012); NOTE 3: For number of entities, the number one, symbol 1, can be regarded as a base unit in any system of units (JCGM 200:2012).


basic local alignment search tool

(BLAST) computer algorithm designed to find regions of local similarity between nucleic acid sequences. The program compares nucleotide sequences with sequence databases and calculates the statistical significance of matches.

Project: MM06


basic safety

protection against direct physical hazards when medical devices are properly used under normal, or reasonably foreseeable, conditions relating, for example, to mechanical strength, biocompatibility, and sterility (ISO Guide 63-2.1)

Project: ISO Guide 63-2.1


batch

defined amount of material that is uniform in its properties and has been produced in one process or series of processes (ISO 18113-1)

Project: ISO CD 18112-1, ISO 18113-1, ISO 18113-2, ISO 18113-4, I/LA28

NOTE: The material can be either starting material, intermediate material, or finished product (ISO 18113-1).


batch

all tubes, plates, or containers of a microbial identification system that have the same lot number and are received in a single shipment (M50).

Project: M50


batch code

distinctive set of numbers and/or letters that specifically identifies a batch and permits its manufacturing,packaging, labeling, and distribution history to be traced (ISO 18113-1)

Project: ISO CD 18112-1, ISO 18113-1, ISO 18113-2, ISO 18113-3


battery

a group of tests ordered together, for example, an admitting battery;

Project: LIS02

NOTE 1: The term "battery" is used in the document synonymously with the term "profile" or "panel"; NOTE 2: The test elements within a battery may be characteristic of a single physiologic system, for example, liver function tests, or many different physiologic systems; NOTE 3: The battery is simply a convention by which a user can order multiple tests by specifying a single name.


battlement pattern

a method of studying a blood film in which the slide is moved from side to side (or end to end) over acceptable examination areas;

Project: H44

NOTE: The cumulative examination pathway resembles the battlement of a castle.


B-cells

one of the two major populations of lymphocytes that display antigen-specific receptors and are involved in humoral immunity and antibody formation

Project: NBS07

NOTE: Normal B-cells can be transformed into continuous cell lines by the Epstein-Barr virus.


B-cells

(B lymphocytes) one of the two major populations of lymphocytes that display antigen-specific receptors and are involved in humoral immunity and antibody formation;

Project: NBS06

NOTE: B-cell progenitors produced in bone marrow differentiate and mature in the bone marrow, spleen, and lymph nodes. During this process, the B-cell progenitors rearrange the regions of their genome containing variable and constant region genes to form sequences that code for the heavy and light chains of immunoglobulin that form their antigen-specific receptors and the secreted antibody.


bead array

created by either impregnating silica or polystyrene beads with different concentrations of fluorescent dye, or by some type of bar-coding technology. The beads are addressable and used to identify specific binding events that occur on their surfaces.

Project: MM22


bead array

created by either impregnating silica beads with different concentrations of fluorescent dye, or by some type of bar-coding technology. The beads are addressable and used to identify specific binding events that occur on their surfaces.

Project: MM19


Bedside Communication Controller

(BCC) specifies the interface (principally input) to an Access Point or concentrator;

Project: POCT01

NOTE: This is an IEEE definition, equivalent to ‘API.’


bedside testing

see point-of-care testing.

Project: POCT13


Beer’s law

the mathematical relationship that defines the amount of radiant energy absorbed by a given substance concentration of a material;

Project: NRSCL8

NOTE: The concentration of a substance is directly proportional to the amount of light absorbed or inversely proportional to the logarithm of the transmitted light; A = e bc = log 100/%T = 2 - log %T; where A = absorbance; e = absorptivity; b = light path length; c = substance concentration; and %T = percent transmittance.


benchmark

a standard or measurement that is used to compare with other similar situations

Project: QMS04


beneficence

the duty to do good and avoid harm to others

Project: GP45

NOTE: The principle of beneficence requires that research design be scientifically sound and that the risks of the research be acceptable in relation to the likely benefits.


benign sequence variation

variations in the genome that are not associated with clinically recognized diseases

Project: NBS05


best measurement capability

the smallest uncertainty of measurement a laboratory can achieve for a stated calibration under specified laboratory conditions.

Project: C43


beta error

probability of falsely rejecting the alternative hypothesis that a substance causes interference when it is true.

Project: EP07


beta error

probability of falsely rejecting the alternative hypothesis when it is true.

Project: C54


beta globulin

one of several groups of blood plasma proteins, divided into fractions, based on electrophoretic mobility somewhat slower than alpha globulin.

Project: DI01


beta hemolysis

the production of a clear zone surrounding a bacterial colony on blood-agar medium, which is characteristic of certain pathogenic bacteria (Cf. POL1/2).

Project: POL1/2


beta-actin (ACTB) gene

the human gene for a nonmuscle cytoskeletal actin isoform;

Project: NBS06

NOTE: A segment of the ACTB gene sequence is used as a genomic reference PCR product in some T-cell receptor excision circle assays.


between-bottle homogeneity

bottle-to-bottle variation of a property of a reference material (ISO Guide 35)

Project: C53

NOTE: It is understood that the term between-bottle homogeneity applies to other types of packages (eg, vials) and other physical shapes and test pieces (ISO Guide 35).


between-group design

a study design in which comparisons are made between study subjects

Project: GP45

NOTE 1: In observational studies, comparisons are made between two or more groups of study subjects with biological risk factors, environmental exposures, diagnoses, treatments, or use of health services; NOTE 2: In experimental studies, comparisons are made between two or more groups of study subjects who are allocated, ideally at random, to clinical treatments or the use of specific health services.


between-subject variation

variation in analyte concentrations among individuals because of differences in factors that cannot be altered within an individual or that last for an extended period of time;

Project: C48

NOTE: This includes factors such as age, sex, race, genetics, or long-term health status.


bias

1) the difference between the expectation of a test result or measurement result and a true value (ISO 5725-1); 2) a quantitative measure of inaccuracy or systematic departure from accuracy under specified conditions of analysis

Project: POCT04

NOTE: Types of bias include:

•Interinstrument (between-instrument) – the difference between the results obtained using two specified instruments;

•Interlaboratory (between-laboratory) – the average difference between the results obtained by two different laboratories performing the same analytical process under specified conditions;

•Inter-measurement procedure  (between-measurement procedure) –  the difference between the results obtained by two specified measurement procedures;

•Of a result – the difference between the result and the true or expected value;

•Of an analytical process – the average difference between the results obtained by the analytical process in question under specified conditions of matrix, analyte concentration, etc., and the true or accepted result; synonym for "systematic error."


bias

(of measurement) estimate of a systematic measurement error(JCGM 2012)

Project: MM21, QMS24, C24, ISO IEC Guide 99, EP25, EP18, C43, H26, NBS04, MM06, H02, EP23, EP29, C56, EP27, EP09, EP26, C40, MM22, EP14, EP15, POCT13, EP19

NOTE 1: In general, the deviation/difference is based on replicate measurement using an accepted (definitive, reference, or designated comparison) method and the method being tested, and expressed in the units of the measurement or as a percentage; NOTE 2: In the context of EP09, bias refers to the estimated, average bias over the measuring interval from a measurement procedure comparison study; NOTE 3: In EP09, the metrological term “bias” is equivalent to the term “difference”; NOTE 4: In EP19, the metrological term “bias” is equivalent to the term “systematic difference; NOTE 5: Difference between the expectation of a test result or measurement result and a true value; NOTE 6: In practice the accepted reference value is substituted for the true value; NOTE 7: Bias represents the quantitative expression of trueness. 


bias

the difference between the expectation of the measurement procedure results and an accepted reference value.

Project: EP33


bias

(of measurements) difference between the expectation of the results of measurement and a true value of the measurand (ISO 17511)

Project: ISO 17511

NOTE: An estimator is the "statistical sample bias of measurements," which is the "average minus its reference value" (ISO 17511).


bias

difference between the expectation of the test results and an accepted reference value (ISO 5725-1)

Project: ISO 3534-1, POCT14, EP07, ISO 15197, ISO 17593, EP06, EP10, ISO 15198, ISO 5725-1, EP17, ILA23, C58, C48, ISO DIS 17593, MM12, H20, C49, C54, C50, EP12, POCT05, H57, C34, H26, MM06, GP34, NBS05, MM20, H60, C57, POCT06

NOTE 1: Bias is the total systematic error, as contrasted to random error. There may be one or more systematic error components contributing to the bias. A larger systematic difference from the accepted reference value is reflected by a larger bias value (ISO 5725-1:1994); NOTE 2: The measure of trueness is usually expressed in terms of bias (ISO 3534-1); NOTE 3: Bias is the numerical counterpart of trueness (EP10); NOTE 4: If the comparison method is a reference method, then the difference between the two methods measures the trueness of the new method, measured as bias. If the comparison method is not a reference method, then the trueness of the new method cannot be determined. In this case, one refers to the difference simply as a difference, and not bias; NOTE 5: Bias is a measure of trueness.


bias

estimate of a systematic measurement error (JCGM 200:2012)

Project: H48, MM10

NOTE: The bias of a measuring instrument is normally estimated by averaging the error of indication over an appropriate number of repeated measurements.


bias

1) lack of validity; the degree to which a study fails to measure what it is designed to measure, due to deviation of results or inferences from the truth, or processes leading to such deviation; 2) any trend in the collection, analysis, interpretation, publication, or review of data that can lead to conclusions that are systematically different from the truth. Ways in which this deviation from the truth can occur include: a) systematic (one-sided) variation of measurements from the true values (also known as “systematic error”); b) variation of statistical summary measures (means, rates, measures of association, etc.) from their true values as a result of systematic variation of measurements, other flaws in data collection, or flaws in study design or analysis; c) deviation of inferences from the truth as a result of flaws in study design, data collection, or the analysis or interpretation of results; d) a tendency of procedures (in study design, data collection, analysis, interpretation, review or publication) to yield results or conclusions that depart from the truth; e) prejudice leading to the conscious or unconscious selection of study procedures that depart from the truth in a particular direction or to one-sidedness in the interpretation of results

Project: GP45

NOTE: Many different types of study bias have been described, including systematic distortion of the estimated intervention effect away from the "truth," caused by inadequacies in the design, conduct, or analysis of a trial.


bias

a quantitative measure of inaccuracy or systematic departure from accuracy under specified conditions of analysis;

NOTE: Types of bias include: interinstrument (between-instrument) - the difference between the results obtained using two specified instruments. intermethod (between-method) - the difference between the results obtained by two specified methods. interlaboratory (between-laboratory) - the average difference between the results obtained by two different laboratories performing the same analytical process under specified conditions. of an analytical process - the average difference between the results obtained by the analytical process in question under specified conditions of matrix, analyte concentration, etc., and the true or accepted result; synonym for “systematic error.” • of a result – the difference between the result and the true or expected value.


bias

(of measurement) difference between the expectation of a test result or measurement result and a true value (ISO 3534-2)

Project: EP21, C62

NOTE 1: Bias is an estimate of a systematic measurement error (JCGM 200:2012). Because trueness, the agreement between a measured value and a reference value, is a concept and cannot be expressed numerically, it is estimated using bias; NOTE 2: In some measurement procedure comparison studies, when bias is relatively constant and in the same direction (positive or negative), bias can be expressed as an average over the entire measuring interval.


bias

the systematic {signed} deviation of the test results from the accepted reference value;

Project: NRSCL08, C44

NOTE: In general, the deviation/difference is based on replicate measurement using an accepted (definitive, reference, or designated comparison) method and the method being tested, and expressed in the units of the measurement or as a percentage.


bicarbonate

In clinical chemistry, the substance concentration of bicarbonate ion is reported in plasma, in equilibrium with fresh erythrocytes under specified conditions; cHCO-3= (ctCO2 - cCO2); LogcHCO -3= pH – pK'+ log PCO2+log aCO2;

Project: C12, C27, C32

NOTE 1: This is not measured directly, rather, it is the result of one or more calculations based on measurement and/or assumptions of the substance concentration of total carbon dioxide, pH, and carbon dioxide tension in plasma under specified conditions; NOTE 2: The concentration of bicarbonate determined by the equations is that in plasma water (Cf. C12, C27, C32).


bicarbonate

(HCO3) a salt of carbonic acid, containing the HCO3-group.

Project: NRSCL8


bidding and negotiations

fifth design phase of the construction project, in which the drawings and specifications are sent to the contractor for bids on the overall project cost

Project: QMS04


bidirectional

bidirectional systems or devices can both send (results, QC, etc.) from the devices to the observation reviewer and receive data (like operator lists) from the observation reviewer to the device, as opposed to devices that can only send results (unidirectional) (CLSI document POCT02).

Project: POCT02


bidirectional interface

a parallel interface that can transfer data in both directions; for example, the transfer of information from the LIS or BECS to the automated system and from the automated system back to the LIS or BECS;

Project: ILA33

NOTE: See interface.


binding capacity

within the context of I/LA20, the binding capacity refers to the number of human immunoglobulin E antibody molecules that an allergen-containing reagent (eg, allergosorbent, liquid-phase allergen) can bind reproducibly under standardized assay conditions (pH, ionic strength, protein matrix, time, temperature)

Project: I/LA20

NOTE: The binding capacity of a reagent is highly dependent on the number of immunoreactive allergen molecules and individual epitopes attached to the solid phase or present in the solution phase reagent. For manufacturers, the goal is to identify allergen-containing reagent preparation conditions that produce maximal binding of allergen to the reagent solid phase in a relevant and reproducible manner.


binding capacity

in Immunology, the capacity of a receptor, such as an antibody, to bind a ligand, such as an antigen (Cf. DI1).

Project: DI01


binding capacity

within the context of I/LA20 and I/LA34, the binding capacity refers to the number of human IgE antibody molecules that an allergen-containing reagent (eg, allergosorbent, liquid-phase allergen) can bind reproducibly under standardized assay conditions (pH, ionic strength, protein matrix, time, temperature);

Project: ILA34

NOTE: The binding capacity of a reagent is highly dependent on the number of immunoreactive allergen molecules and individual epitopes attached to the solid phase or present in the solution phase reagent. For manufacturers, the goal is to identify allergen-containing reagent preparation conditions that produce maximal binding of allergen to the reagent solid phase in a relevant and reproducible manner.


binning

general term for a classification process that groups objects into sets based on defined parameters of similarity.

Project: MM09


biobanking

collection of biological material (blood, tissue, or other) from one or several human beings obtained and stored indefinitely or for a specified time, and whose origin is traceable to the humans from whom it originates

Project: GP44


biocide

a chemical or physical agent that kills microorganisms

Project: GP40


biofilm

microorganisms, enclosed in a glycoprotein/polysaccharide matrix, that adhere to each other and/or to surfaces and may form macroscopic layers

Project: GP40


biohazard

a biological agent or condition that constitutes a hazard to human beings, animals, or their environment

Project: QMS04


biohazard

a biological agent or condition that constitutes a hazard to human beings or their environment

Project: POCT04, AST02, HS02, POCT10


biohazard (biological hazard)

a biological agent, material, or condition that constitutes a hazard to human beings or their environment;

Project: M29

NOTE: Potential source of harm caused by biological agents or toxins (CWA 15793).


biologic

a drug that is prepared using a biological starting or source material (i.e., derived from a microorganism, plant, or animal) and various manufacturing techniques.

Project: HS11


biological agent

any microorganism, including those which have been genetically modified, cell cultures and human endoparasites, which may be able to provoke any infection, allergy, or toxicity (ISO 15190)

Project: ISO 15190, M29

NOTE 1: For classification of biological agents into risk groups, see Clause 4 of ISO 15190; NOTE 2: For the purposes of M40, proteinaceous infectious particles are regarded as "biological agents" (CWA 15793).


biological product

a substance that originated from living organisms (including humans and other mammals) and has been manufactured and distributed in accordance with compliance and licensing requirements set forth by the federal government; can be classified as an infectious substance if such is appropriate;

Project: M29

NOTE: Biological products are intended for use in the prevention, treatment, or diagnosis of disease in humans or animals and may be used for investigational, experimental, or development purposes.


biological reference interval

specified interval of the distribution of values taken from a biological reference population (ISO 15189)

Project: I/LA02, ISO 15189

NOTE 1: Terms such as 'normal range', 'normal values', and 'clinical range' are ambiguous and therefore discouraged; NOTE 2: A reference interval is commonly defined as the central 95% interval. Another size or an asymmetrical location of the reference interval could be more appropriate in particular cases.


biological reference interval

interval between, and including, the lower reference value limit and the upper reference value limit of the biological reference population; EXAMPLE The biological reference interval for glucose measurements in plasma from fasting subjects in a population of healthy male and female adults is from 3.6 to 6.1 mmol/L

Project: POCT17, ISO/CD 18113-1, ISO/CD 18113-2, ISO/CD 18113-3

NOTE 1: A biological reference population is a homogeneous population of individuals in a well-defined state of health or disease, which can be a defined group of apparently healthy individuals or individuals with a specific medical condition. The concept allows for relating the reference interval to age, gender, and ethnicity of the reference population, as appropriate; NOTE 2: The type of samples used to determine the reference intervals and the examination procedure used for their determination should be reported; NOTE 3: Biological reference intervals in clinical and occupational medicine are conventionally defined as a 0.95 coverage interval with a confidence of 0.95, which serves as a prediction interval where the probability of a future observation from the distribution being included in the interval is equal to the expectation. Consequently, an observation outside the coverage interval can be considered unusually high (or low), and further scrutiny is needed to establish whether the patient is at increased health risk; NOTE 4: In some cases, only one biological reference limit is important, usually an upper limit, "x," and the corresponding biological reference interval would be less than or equal to” x”;NOTE 5: Terms such as "normal range" and "normal values" are considered obsolete. [IFCC]


biological reference interval

specified interval of the distribution of values taken from a biological reference population (ISO 18113-1)

Project: ISO 18113-1

EXAMPLE: The 0.95 biological reference interval for sodium ion concentration values in serum from a population of healthy male and female adults is 135 to 145 mmol/L (ISO 18113-1); NOTE 1: A reference interval is commonly defined as the central 95% interval. Another size or an asymmetrical location of the reference interval could be more appropriate in particular cases (ISO 18113-1); NOTE 2: A reference interval can depend upon the type of primary samples and the examination procedure used (ISO 18113-1); NOTE 3: In some cases, only one biological reference limit is important, usually an upper limit, "x," so that the corresponding biological reference interval would be less than or equal to "x" (ISO 18113-1); NOTE 4: Terms such as “normal range,” “normal values” and "clinical range" are ambiguous and therefore discouraged (ISO 18113-1); NOTE 5: Adapted from: CLSI document C28; International Federation of Clinical Chemistry, International Committee for Standardization in Haematology. Approved recommendation (1986) on the theory of reference values. Part 1. Theconcept of reference values. Clin Chim Acta. 1987;167:111-118; International Federation of Clinical Chemistry, International Committee for Standardization in Haematology. Approved recommendations (1987) on the theory of reference values. Part 5. Statistical treatment of collected reference values. Determination of reference limits. J Clin Chem Clin Biochem. 1987;25:645-656; and Poulsen OM, Holst E, Christensen JM. Calculation and application of coverage intervals for biological reference values (technical report) — A supplement to the approved IFCC recommendation (1987) on the theory of reference values. Pure Appl Chem. 1997;69(7)1601-1611 (ISO 18113-1); NOTE 6: Interval between, and including, the lower reference limit to the upper reference limit of the reference population (eg, 95% of persons presumed to be healthy [or normal]); NOTE 7: For genomic copy number (CN) microarrays, the range of CN variants and absence of heterozygosity that occur in the normal healthy population. Also see reference range.


biological reference population

group of individuals in a well-defined state of health or disease (ISO 18113-1)

Project: ISO 18113-1

NOTE 1: When biological reference intervals are provided by a manufacturer in the instructions for use, laboratories using the IVD medical device are responsible for verifying that the biological reference populations represent the populations serviced by the laboratories (ISO 18113-1); NOTE 2: A biological reference population can be a defined homogenous group of apparently healthy individuals or individuals with a specific medical condition. The concept allows for relating the reference interval to age, gender and ethnicity of the reference population, as appropriate (ISO 18113-1); NOTE 3: Adapted from: CLSI document C28; International Federation of Clinical Chemistry, International Committee for Standardization in Haematology. Approved recommendation (1986) on the theory of reference values. Part 1. Theconcept of reference values. Clin Chim Acta. 1987;167:111-118; International Federation of Clinical Chemistry, International Committee for Standardization in Haematology. Approved recommendations (1987) on the theory of reference values. Part 5. Statistical treatment of collected reference values. Determination of reference limits. J Clin Chem Clin Biochem. 1987;25:645-656; and Poulsen OM, Holst E, Christensen JM. Calculation and application of coverage intervals for biological reference values (technical report) — A supplement to the approved IFCC recommendation (1987) on the theory of reference values. Pure Appl Chem. 1997;69(7)1601-1611 (ISO 18113-1).


biological safety

describes the containment principles, technologies, and practices that are implemented to prevent the unintentional exposure to biological agents and toxins or their accidental release (CWA 15793).

Project: M29


biological safety cabinet

(BSC) hood designed specifically to contain microorganisms

Project: QMS04

NOTE 1: They are designed to protect workers, the environment, and laboratory consumables from contamination; NOTE 2: They can also be designed to use small amounts of chemicals and to keep products in the hood clean.


biological safety cabinet

See microbiological safety cabinet.


biological safety cabinet

a ventilated cabinet for personnel, product, and environmental protection having an open front with an inward airflow for personnel protection, downward high-efficiency particulate air (HEPA)–filtered laminar airflow for product protection, and HEPA-filtered exhausted air for environmental protection.

Project: M29


biological safety level

combinations of laboratory practices and techniques, safety equipment, and laboratory facilities. Each combination is specifically appropriate for the performed operations, the documented or suspected routes of transmission of the infectious agents, and the laboratory function or activity.

Project: M29, GP36


biological select agents and toxins

see select agent.

Project: M29


biological substance, Category B

any infectious substance that does not meet the criteria of a Category A substance; an infectious substance not in a form generally capable of causing disability, life-threatening illness, or fatal disease;

Project: M29

NOTE 1: Category B substances generally are 1) patient and clinical specimens reasonably expected to contain a non–Category A pathogen; and 2) cultures of microorganisms not specifically listed in Category A; NOTE 2: The United Nations number and proper shipping name for a Category B substance is Biological Substance, Category B.


biological variation

consists of within-subject (CVI, intraindividual) and between-subject (CVG, interindividual, group) variation.

Project: EP33


biomarker

a specific analyte (DNA, RNA, protein) found in a patient specimen that is useful for measuring the progress of disease or the effects of treatment.

Project: MM13, MM23


biomarker

a compound that is objectively measured and evaluated as an indicator of normal biological or pathogenic processes or pharmacological responses to a therapeutic intervention

Project: NBS04

NOTE 1: In the context of NBS04, a biomarker is a chemical entity that can be quantified and in which there is a relationship between the amount of that entity and some pathogenic, pharmacological, or therapeutic event; NOTE 2: Also called “marker”; NOTE 3: See primary markers and secondary markers.


biomarker

a characteristic or compound that is objectively measured and evaluated as an indicator of normal biologic or pathogenic processes or pharmacologic responses to a therapeutic intervention

Project: C50

NOTE: In the context of C50, a biomarker is a chemical entity that can be quantified, and in which there is a relationship between the amount of that entity and some pathogenic, pharmacologic, or therapeutic event.


biomarker

any feature of a patient that is useful for measuring the risk of developing, presence, or progression of disease or the effects of treatment;

Project: I/LA28

NOTE: Frequently, biomarkers are biomolecules (proteins, nucleic acids, or other biomolecules) that are obtained from the patient and subject to direct analysis.


biomass

biological material from organisms

Project: M58

NOTE: In the context of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for microorganism identification, “biomass” refers to the microorganisms themselves.


biometrics

the measurement and analysis of unique physical characteristics of an individual (eg, fingerprints, voice pattern, retinal scan) as a means of verifying personal identity.

Project: AUTO11


biopolymers

a macromolecule in a living organism that is formed by linking together several smaller molecules (eg, DNA, RNA, polysaccharides, proteins, and peptides) (CLSI document C50).

Project: C50


biopsy

the medical removal of tissue from a living subject to determine the presence or extent of a disease.

Project: MM23


biorepository

a repository or storage facility or archive of biological specimens including tissue, serum, plasma, and other fluids.

Project: I/LA28


biosafety

See "biological safety."

Project: M29


biosafety cabinet

see biological safety cabinet.

Project: M29


biosafety level

(BSL) combinations of laboratory practices and techniques, safety equipment, and laboratory facilities. Each combination is specifically appropriate for the performed operations, the documented or suspected routes of transmission of the infectious agents, and the laboratory function or activity

Project: QMS04, GP26, M54

NOTE 1: This is subdivided into four levels (BSL-1, BSL-2, BSL-3, BSL-4) for microbiological and biomedical laboratories; NOTE 2: In the United States and Europe, this is subdivided into four levels (BSL-1, BSL-2, BSL-3, BSL-4) for microbiological and biomedical laboratories.


biosafety level

see biological safety level.

Project: M29, GP36


biosafety level 1

(BSL-1; Canadian, containment level [CL] 1 laboratory) practices, safety equipment, and facility design and construction for work involving well-characterized agents not known to consistently cause disease in healthy adult humans, and of minimal potential hazard to laboratory personnel and the environment;

Project: MM19

NOTE 1: It includes several kinds of bacteria and viruses including canine hepatitis, nonpathogenic Escherichia coli, as well as some cell cultures and noninfectious bacteria; NOTE 2: At this level, precautions against the biohazardous materials in question are minimal, most likely involving gloves and some sort of facial protection.


biosafety level 2

(BSL-2) practices, safety equipment, and facility design and construction that are applicable to clinical, diagnostic, teaching, and other laboratories in which work is done with the broad spectrum of indigenous moderate-risk agents that are present in the community and associated with human disease of varying severity.

Project: GP36


biosafety level 2

(BSL-2; Canadian, containment level [CL] 2 laboratory) practices, safety equipment, and facility design and construction for work involving agents of moderate potential hazard to personnel and the environment;

Project: MM19

NOTE 1: It includes various bacteria and viruses that cause only mild disease to humans, or are difficult to contract via aerosol in a laboratory setting, such as Clostridium difficile; hepatitis A, B, and C; influenza A; Lyme disease; dengue fever; Salmonella; mumps; measles; human immunodeficiency virus; scrapie; methicillin-resistant Staphylococcus aureus; and vancomycin-resistant S. aureus; NOTE 2: Genetically modified organisms have also been classified as BSL-2 organisms, even if they pose no direct threat to humans. This designation is used to limit the release of modified organisms into the environment. In the United States, US Food and Drug Administration approval is required to release these organisms.


biosafety level 3

(BSL-3) practices, safety equipment, and facility design and construction that are applicable to clinical, diagnostic, teaching, research, or production facilities in which work is done with indigenous or exotic agents with a potential for respiratory transmission, and which may cause serious and potentially lethal infection.

Project: GP36


biosafety level 3

(BSL-3; Canadian, containment level [CL] 3 laboratory) practices, safety equipment, and facility design and construction that are applicable to clinical, diagnostic, teaching, research, or production facilities in which work is done with indigenous or exotic agents with a potential for respiratory transmission, and which may cause serious and potentially lethal infection;

Project: MM19

NOTE: It includes various bacteria and viruses that can cause severe to fatal disease in humans, but for which vaccines or other treatment exist, such as Mycobacterium tuberculosis, Bacillus anthracis, West Nile virus, Venezuelan equine encephalitis virus, Eastern equine encephalitis virus, Hendra virus, severe acute respiratory syndrome coronavirus, Coxiella burnetii, Rift Valley fever virus, Rickettsia rickettsii, and yellow fever virus.


biosafety level 4

(BSL-4) practices, safety equipment, and facility design and construction that are required for work with dangerous and exotic agents that pose a high individual risk of aerosol-transmitted laboratory infections and life-threatening diseases that are frequently fatal and for which there are no vaccines or treatments or a related agent with unknown risk of transmission.

Project: GP36


biospecimen

a biological sample fluid or tissue obtained from an organism.

Project: I/LA28


bioterrorism

biological diseases and the select agents that might be used for terrorism

Project: QMS04

NOTE: Select agents are very varied and comprise viruses, bacteria, rickettsiae (microorganisms that have traits common to both bacteria and viruses), fungi, and biological toxins.


biotin

a 241-dalton molecule that can be attached covalently to lysine residues of proteins;

Project: I/LA28

NOTE 1: Owing to its small size, it has minimal impact on the protein to which it is conjugated. The proteins avidin and streptavidin have a high affinity for biotin; NOTE 2: This property can be used in many detection systems.


biotin

a molecule that can be covalently attached to lysine residues of proteins;

Project: NRSCL8

NOTE: This property is used in many detection systems (Cf. MM04).


biphasic blood culture system

a blood culture system in which a single container (vial) has separate chambers for solid- and liquid-based media;

Project: M47

NOTE: Most biphasic systems are designed so that the solid medium can be irrigated with the liquid medium.


blank

(nontemplate control [NTC]) the apparent amount or concentration of an analyte measured by an analytical process when an analyte is omitted from a tested sample or when the tested sample is known to contain none of the analyte; a combination of the individual “blanks,” such as the extraction blank and the reagent blank, as appropriate for the assay.

Project: NRSCL8, MM10, MM03


blank

sample that does not contain the analyte of interest, or has a concentration at least an order of magnitude less than the lowest level of interest;

Project: EP17, H58

NOTE: In the context of this document, in most cases, this is platelet-poor plasma (PPP) (CLSI document H58).


blank

(no template control) the apparent amount or concentration of a measurand measured by an analytical process when a measurand is omitted from a tested sample or when the tested sample is known to contain none of the measurand; a combination of the individual “blanks,” such as the extraction blank and the reagent blank, as appropriate for the assay.

Project: MM22


blank indication

indication obtained from a phenomenon, body, or substance similar to the one under investigation, but for which a quantity of interest is supposed not to be present, or is not contributing to the indication (JCGM 200:2012)

Project: ISO IEC Guide 99


BLAST

abbreviation for Basic Local Alignment Search Tool, a computer program that identifies homologous genes in different organisms (MM18).

Project: MM18


blastoconidium

(pl. blastoconidia) a conidium that is formed by budding from a hyphal, pseudohyphal, or yeast cell.

Project: M54


blind subcultures

subcultures performed as a routine laboratory procedure irrespective of any objective evidence of microbial growth.

Project: M47


blind subpassage

transfer of cells and/or medium from an existing viral culture to a fresh cell culture monolayer(s)

Project: M41


blinding

the practice of keeping the trial participants, care providers, those collecting data, and sometimes even those analyzing data unaware of which intervention is being administered to which participant

Project: GP45, GP45

NOTE 1: Blinding is intended to prevent bias on the part of study personnel; NOTE 2: A very common application is "double-blinding," in which participants, caregivers and investigators, and those collecting data are blinded to knowledge of the intervention that is administered; in "triple blinding," those persons assessing outcome and analyzing the outcomes are blinded to intervention assignment.


block cipher

an encryption algorithm that breaks plaintext into fixed-size segments and uses the same key to transform each plaintext segment into a fixed-size segment of ciphertext. (See: stream cipher.) (RFC 2828)

Project: AUTO09


block diagram

graphic illustration of the spaces in a project and how they might fit into a designated area in the facility

Project: QMS04

NOTE: This diagram is the very rough beginning of a floor plan.


blocking

the reaction of uncomplexed binding sites or of coupling agents to prevent nonspecific binding of test reactants (MM04).

Project: MM04


blocking

any inhibition of reaction that possibly may have occurred in the assay that would have resulted in inferior assay signal or result;

Project: I/LA28

NOTE: Examples of blocking reaction include (1) the reaction of endogenous peroxidase in a tissue specimen with the intent of destroying enzyme activity; and (2) blocking of nonspecific binding of antibody reagents.


blood

(capillary) blood collected after puncturing any of the minute vessels that connect the arterioles and venules, often obtained by pricking a fingertip; capillary blood is usually collected without additives such as anticoagulants or preservatives; therefore, it is inherently unstable

Project: ISO CD 17593, ISO/DIS 17593


blood

the “circulating tissue” of the body that consists of plasma in which are suspended cells, nutrients, metabolic products, and oxygen.


blood

(occult) blood present in very small amounts; usually detectable by chemical means; specimen is most often stool; may or may not be related to parasitic infection

Project: M28


blood

the circulating intravascular tissue of the body, consisting of suspended formed elements and fluid plasma (ISO 17593)

Project: POCT04, ISO 17593

NOTE: In ISO 17593, the term refers to fresh, nonanticoagulated blood.


blood

(venous) blood collected after directly puncturing a vein, usually with a needle and syringe, or other collection device; venous blood may be collected without additives such as anticoagulants or preservatives, and if so, will be inherently unstable; venous blood may also be collected into containers containing additives or preservatives with the intent to stabilize specific components

Project: ISO CD 17593


blood

circulating intravascular component of the body, consisting of suspended formed elements and fluid plasma (modified from ISO 17593)

Project: POCT13

NOTE: In ISO 17593, the term refers to fresh, nonanticoagulated whole blood.


blood collection device

a capped tube that contains a vacuum (otherwise known as an evacuated tube) usually held by an adaptor with an attached needle, syringe, or other device with a nonactivating surface used to collect a blood sample with the use of a needle assembly (H21).

Project: H21


blood collection system

a system consisting of several components, such as catheter, connecting device, syringe, needle, and collection device, used for blood collection (H21).

Project: H21


blood culture

a specimen of blood that is submitted for bacterial or fungal culture;

Project: M47

NOTE: This is irrespective of the number of bottles or tubes into which the specimen is divided or distributed.


blood culture series

a group of temporally related blood cultures that are collected to determine whether a patient has bacteremia or fungemia

Project: M47


blood culture set

the combination of blood culture bottles or tubes into which a single blood specimen is inoculated.

Project: M47


Blood Establishment Computer Software

(BECS) the software that is part of a blood establishment computer system, which is used by blood establishments (human blood and plasma donor centers, blood banks, transfusion services and other blood product manufacturers, and independent laboratories) in the manufacture and/or transfusion of blood and blood components;

Project: ILA33

NOTE 1: It is designed to receive and store data used by blood establishments during the manufacturing process, from determining donor suitability through component processing, testing, and labeling to product release. It is designed to receive and store data regarding blood donor status, including donors’ answers to health history questions and the results of laboratory tests, such as blood grouping and typing, hepatitis, and antibody to HIV. Blood establishment personnel later access and use the data to determine if donors are suitable and if blood or blood components are free from disease-causing agents transmissible by blood, such as hepatitis and HIV. In addition, the data are used to label blood and blood components prior to release for use in hospitals and other health care facilities or for further manufacturing; NOTE 2: This software may be manufactured either in-house or by a software manufacturer or vendor; NOTE 3: For the purposes of this document, references to the LIS can be interpreted to mean BECS, as appropriate.


blood glucose meter

component of a blood-glucose monitoring system that converts the result of a chemical reaction into the glucose concentration of the sample (modified from ISO 15197)

Project: ISO 15197, POCT07


blood glucose monitoring system

measuring system consisting of a portable instrument and reagents used for the in vitro monitoring of glucose concentrations in blood (ISO 15197)

Project: ISO 15197

NOTE: Blood glucose monitoring systems measure glucose in capillary blood samples, but may express results as either the glucose concentration in blood or the equivalent glucose concentration in plasma. Concentrations in this International Standard refer to the type of results reported by the system (modified from ISO 15197).


blood specimen

the discrete portion of blood taken for examination, study, or analysis of one or more quantities or characteristics to determine the character of the whole

Project: POCT17, POCT13


blood specimen

(arterial) blood obtained by arterial puncture or from an individual arterial line, catheter, or extracorporeal circuit

Project: POCT17, POCT13


blood specimen

(capillary) blood collected after puncturing any of the minute vessels that connect the arterioles and venules, often obtained by pricking a fingertip; capillary blood is usually collected without additives such as anticoagulants or preservatives, therefore, it is inherently unstable (modified from ISO 17593)

Project: POCT17, POCT13


blood specimen

(venous) blood collected after directly puncturing a vein, usually with a needle and syringe, or other collection device or from an indwelling catheter or line (modified from ISO 17593)

Project: POCT17, POCT13


bloodborne pathogens

pathogenic microorganisms that are present in human blood, blood products, or other potentially infectious material contaminated with blood, and can cause disease in humans or animals

Project: QMS04


bloodborne pathogens

pathogenic microorganisms that are present in human blood and can cause disease in humans

Project: X3

NOTE: These pathogens include, but are not limited to, hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV).


bloodborne pathogens

pathogenic microorganisms that are present in human blood and can cause disease in humans (29 CFR 1910.1030).

Project: M29


bloodstream infection

an infection associated with bacteremia or fungemia

Project: M47


bone alkaline phosphatase

an enzyme found in osteoblasts;

Project: C48

NOTE 1: It has a molecular weight of approximately 140 000 Da; NOTE 2: It is distinguishable from other alkaline phosphatases by its oligosaccharide side chain.


bone formation

the deposition of new bone, including bone mineral and bone matrix components.

Project: C48


bone marker

biochemical substance produced or released during bone turnover;

Project: C48

NOTE: It can be measured in urine, blood, or other body fluids.


bone resorption

the process of removal of bone tissue, including bone mineral and bone matrix components

Project: C48


Boolean logic

developed by George Boole in the mid-1800s, operates on a set of rules that provides a consistent output based on a predefined set of input parameters;

Project: AUTO10

NOTE: The rules can be easily defined in a set of logic tables or diagrams. The most common rules are AND, OR, NAND, and NOR logic statements.


bootstrap

a way of testing the reliability of a dataset; a statistical method for obtaining an estimate of error that is used to evaluate the reliability of a phylogenetic tree.

Project: MM10


borderline antimicrobial susceptibility test interpretive category

an interpretive category applicable only to certain results obtained with MTBC isolates tested against pyrazinamide by the radiometric instrument method (refer to the manufacturer’s package insert);

Project: M24

NOTE: Repeat testing may determine whether the isolate in question is susceptible or resistant.


borderline positive

a test result that is neither positive nor negative, and thus the test has to be repeated or the results verified or extended by a confirmatory assay

Project: I/LA18


bottom of cap

the farthest point from the top of the container/test tube that the cap reaches;

Project: AUTO01, AUTO02, AUTO07, AUTO12

NOTE: This point may be inside the tube.


bottom of container

the portion of the container/test tube farthest from the cap.

Project: AUTO01, AUTO02, AUTO07, AUTO12


bottom of tube

See bottom of container.

Project: AUTO02, AUTO12


bound fraction

the fraction of total analyte bound to receptor (Cf. LA1)

Project: LA01


bound ratio

in Immunology, the ratio of receptor-bound to nonreceptor-bound (free), labeled analyte in an immunoassay (Cf. DI1).

Project: DI01


boundary

as used in this document, an absolute limit to the measurement response reading from an instrument;

Project: I/LA24

NOTE 1: Boundaries apply particularly to digitized data expressed in histograms, where the zero channel and the maximum channel define absolute limits to the readings obtained from the instrument; NOTE 2: Boundaries for fluorescence intensity calibration curves are often expressed in units of analyte dose as extrapolated from a calibration curve to the minimal or maximal possible reading on the instrument scale; lower boundary - the analyte dose extrapolated from a calibration curve to the lowest possible reading from an instrument; NOTE 3: The lower boundary is a theoretical value and should not be taken as a true measurement of instrument sensitivity. However, the actual sensitivity of the instrument can never be less than the lower boundary.


breakage

loss of vessel integrity due to the production of unintentional cracks or openings in the vessel’s walls.

Project: M40


breakpoint

minimal inhibitory concentration (MIC)/minimal effective concentration or zone diameter value used to categorize an organism as susceptible, susceptible-dose dependent, intermediate, nonsusceptible, or resistant  

NOTE 1: MIC or zone diameter values generated by a susceptibility test can be interpreted based upon established breakpoints; NOTE 2: See interpretive category.


breakpoint

minimal inhibitory concentration (MIC) or zone diameter value used to categorize an organism as susceptible, intermediate, nonsusceptible, or resistant

NOTE 1: MIC or zone diameter values generated by a susceptibility test can be interpreted based upon established breakpoints; NOTE 2: See interpretive category.


breakpoint

minimal inhibitory concentration (MIC) or zone diameter value used to categorize an organism as susceptible, susceptible-dose dependent, intermediate, nonsusceptible, or resistant

NOTE 1: MIC or zone diameter values generated by a susceptibility test can be interpreted based upon established breakpoints; NOTE 2: See interpretive category.


breakpoint

(BP) specific values of parameters, such as MICs, on the basis of which bacteria can be assigned to the clinical categories "susceptible," "intermediate," and "resistant" (ISO 20776-1)

Project: ISO 20776-1, ISO 20776-2

NOTE: For current interpretive breakpoints, reference can be made to the latest publications of organizations employing this reference method (eg, CLSI and EUCAST) (ISO 20776-1). 


breakpoint

minimal inhibitory concentration (MIC) or zone diameter value used to categorize an organism as susceptible, intermediate, nonsusceptible, or resistant

Project: VET06

NOTE 1: MIC or zone diameter values generated by a susceptibility test can be interpreted based upon established breakpoints; NOTE 2: See interpretive category.


breakpoint

see interpretive criteria.

Project: VET01, M02, M07


breakpoint criteria

MIC or zone diameter value used to indicate susceptible, intermediate, and resistant as defined by the interpretive criteria used in CLSI documents M2—Performance Standards for Antimicrobial Disk Susceptibility Tests; M7—Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; and M11—Methods for Antimicrobial Susceptibility Testing of Anaerobic Bacteria. For example, for antimicrobial X with interpretive criteria of:
Susceptible: MIC = ≤4 µg/mL and Zone Diameter = ≥20 mm
Intermediate: MIC = 8-16 µg/mL and Zone Diameter = 15-19 mm
Resistant: MIC = ≥32 µg/mL and Zone Diameter = ≤14 mm
"Susceptible breakpoint" is 4 µg/mL or 20 mm.
"Resistant breakpoint" is 32 µg/mL or 14 mm (CLSI document M39).


breakpoint test

(BPT) test that has the principal objective to provide categorical results (SIR) (ISO 20776-2)

Project: ISO 20776-2

NOTE: This can include limited range dilution tests or diffusion tests (ISO 20776-2).


breakthrough bacteremia

bacteremia that persists while a patient is receiving antimicrobial therapy for an episode of bacteremia;

Project: M47

NOTE 1: Breakthrough bacteremia that occurs early usually is the result of inappropriate or inadequate antimicrobial therapy; NOTE 2: Breakthrough bacteremia that occurs late usually is the result of a focus of infection (e.g., an abscess) that has not been drained adequately.


brefeldin A

(BFA) a relatively nontoxic but potent protein inhibitor of intracellular protein transport.

Project: I/LA26


British thermal unit

(BTU) the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit

Project: QMS04

NOTE: This measurement is used to describe the heating or cooling capacity of a system.


broker

a consultant, contractor, or waste transport firm that evaluates waste material, determines the appropriate disposal method, and makes arrangements for transport and disposal.

Project: GP05


broth

fluid medium used for the in vitro growth of bacteria (ISO 20776-1)

Project: ISO 20776-1


broth dilution

technique in which containers are filled with appropriate volumes of an antimicrobial solution, employing incrementally (usually two-fold) increasing concentrations of the antimicrobial agent and appropriate volumes of broth with a defined inoculum (ISO 20776-1)

Project: ISO 20776-1

NOTE: The aim of this method is the determination of the MIC (ISO 20776-1).


broth dilution susceptibility test

an in vitro antimicrobial susceptibility test method conducted using serial concentrations of an antimicrobial agent incorporated in liquid nutrient media that are inoculated with a bacterial suspension to determine the MIC of the antimicrobial agent. When this procedure is carried out in test tubes, it is referred to as broth macrodilution; when performed in microdilution plates, it is called broth microdilution (M37).

Project: VET02


broth dilution susceptibility test

an antimicrobial susceptibility test conducted using serial concentrations of an antimicrobial agent incorporated into a broth growth medium, in separate test tubes or in the wells of a microtitration tray


broth dilution susceptibility test

an in vitro antimicrobial susceptibility test conducted using serial concentrations of an antimicrobial agent incorporated in liquid nutrient media that are inoculated with a bacterial suspension to determine the minimal inhibitory concentration of an antimicrobial agent;

Project: VET05

NOTE: When this procedure is carried out in test tubes, it is referred to as broth macrodilution; when performed in microdilution plates, it is called broth microdilution.


broth microdilution technique

the method of antimicrobial susceptibility testing that is based on preparation of a liquid broth medium containing various concentrations of antimicrobial agents into which a defined inoculum of microorganisms is inoculated and then incubated and observed for growth.

Project: M43


bubble diagram

graphic illustration, using circles, of the required relationships between various spaces in a project

Project: QMS04


buffer

a solution or reagent that can resist a change in pH upon addition of either an acid or a base.

Project: MM04, I/LA28


buffy coat

a yellowish-white layer of leukocytes and platelets that forms on top of the column of red blood cells upon centrifugation of whole blood;

Project: NRSCL8

NOTE 1: Defined by WHO-BS/95.1793 as "a blood component rich in leukocytes and platelets, suspended in a small volume of plasma from the same donation"; NOTE 2: It is obtained either by separation from whole blood or by cytopheresis (Cf. H7).


buffy coat

the fraction of a centrifuged blood sample that contains most of the white blood cells;

Project: MM17

NOTE: After centrifugation, one can distinguish a layer of clear fluid (the plasma), a layer of red fluid containing most of the red blood cells, and a thin layer in between, the buffy coat (so-called because it is usually buff in hue), with most of the white blood cells and platelets. The buffy coat is used, for example, to extract DNA from the blood of mammals (since mammalian red blood cells do not contain DNA) (MM17).


building commissioning

the process of verifying that all systems for heating, ventilation, and air conditioning; plumbing; electrical; controls; fire; security; building envelope; and interior materials meet the owner’s requirements as designed by the owner’s design team

Project: QMS04


built-in

anything incorporated into the measuring system by the manufacturer.

Project: EP23


business continuity planning

the creation and validation of a practiced logistical plan for how an organization will recover and restore partially or completely interrupted critical (urgent) functions within a predetermined time after a disaster or extended disruption.

Project: MM19


C50

the analyte concentration near the cutoff that yields 50% positive results and 50% negative results when many replicates of a single sample at that concentration are tested (EP12).

Project: EP12


C5-C95 interval

the range of analyte concentrations around the cutoff such that observed results at concentrations outside this interval are consistently negative (concentrations <C5) or consistently positive (concentrations >C95) (EP12);

Project: EP12

NOTE 1: Observed results at concentrations inside this interval are not consistent due to imprecision (EP12); NOTE 2: These concepts are explained in greater detail in Section 8 (EP12).


CA membrane

a reverse osmosis membrane constructed of cellulose diacetate/triacetate

Project: GP40


calcium ion-selective membrane

the active element of the ISE half-cell that responds to changes in activity of calcium ion in solution;

Project: C39

NOTE: A calcium ion-selective membrane typically contains an ionophore or ion-exchanger and a plasticizer in a plastic matrix such as polyvinyl chloride or polyurethane; other additives may be included to improve membrane functionality.


calibrated assays

the proposed three levels of calibrated immunoglobulin E (IgE) antibody assays are: 1) titration assays that use an arbitrary reference system to define a class or arbitrary value; this category of calibration can reliably discriminate between doubling dilutions, but it does not ensure parallelism; 2) calibrated titration assays, such as IgE antibody assays that are calibrated with a heterologous serum IgE dose-response curve and that generate reliable, reproducible results; these assays behave consistently with respect to parallelism; 3) quantitative assays as represented by the total serum IgE assay but which are not commercially available for IgE antibody quantification;

Project: I/LA20

NOTE: Quantitative assays use a homologous calibrator.  They produce reproducible and accurate results, and behave appropriately with respect to parallelism and recovery. The number of calibrators must be in context with the measurement system. Factory-calibrated procedures, which are often stored in random access memory, may have one or more “adjusters” that normalize response data and can reproducibly and accurately determine analyte concentrations for many immunoassay runs.


calibrated assays

three levels of calibrated IgE antibody assays are proposed as follows: 1) titration assays that use an arbitrary reference system to define a class or arbitrary value; this category of calibration can reliably discriminate between doubling dilutions, but it does not ensure parallelism; 2) calibrated titration assays, such as IgE antibody assays that are calibrated with a heterologous serum IgE dose-response curve and that generate reliable, reproducible results; these assays behave consistently with respect to parallelism; 3) quantitative assays as represented by the total serum IgE assay but which are not commercially available for IgE antibody quantification;

NOTE: These are assays that use a homologous calibrator. They produce reproducible and accurate results, and behave appropriately with respect to parallelism and recovery. The number of calibrators must be in context to the measurement system. Factory-calibrated procedures, which are often stored in random access memory, may have one or more "adjusters" that normalize response data and can reproducibly and accurately determine analyte concentrations for many immunoassay runs.


calibrated assays

two levels of calibrated IgE antibody assays are proposed as follows: 1) titration assays that use an arbitrary reference system to define a class or arbitrary value; this category of calibration can reliably discriminate between doubling dilutions, but it does not ensure parallelism; 2) calibrated titration assays, such as IgE antibody assays that are calibrated with a heterologous serum IgE dose-response curve and which generate reliable, reproducible results; these assays behave consistently with respect to parallelism.

Project: ILA34


calibration

operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication (JCGM 200:2012)

Project: H54, POCT14, H44, EP10, EP10, H54, MM12, QMS07, POCT04, H47, H57, GP40, EP33, H48, QMS24, ISO IEC Guide 99, ILA29, H58, POCT05, EP25, POCT09, ISO 18113-1, H26, H59, M53, C58, MM19, MM01, C54, EP27, MM20, EP26, C40, MM22, EP14, C62, C57, MM23, POCT06, EP19

NOTE 1: A calibration may be expressed by a statement, calibration function, calibration diagram, calibration curve, or calibration table. In some cases, it may consist of an additive or multiplicative correction of the indication with associated measurement uncertainty (JCGM 200:2012); NOTE 2: Calibration should not be confused with adjustment of a measuring system, often mistakenly called "self-calibration," nor with verification of calibration (JCGM 200:2012); NOTE 3: Often, the first step alone in the above definition is perceived as being calibration (JCGM 200:2012); NOTE 4: Calibration is the procedure used, under predefined conditions, to establish a relationship of the sensor glucose measurement to the glucose reading of a predetermined standard (POCT05); NOTE 5: The relationship of the sensor glucose measurement should be established to a biological medium (POCT05); NOTE 6: Some of the factors that should be considered are the conditions under which the sensor can be effectively calibrated, number of measurements that are required under specific conditions for the device to start providing glucose values, and the frequency of subsequent calibrations needed to maintain accuracy over the lifetime of the sensor (POCT05); NOTE 7: Calibration process is performed to meet accuracy claims (POCT05); NOTE 8: Calibration permits either the assignment of values of the measurands to the measurement indications provided by the measuring instrument, or the determination of a correction with respect to the values provided by the measuring instrument (ISO 18113-1); NOTE 9: Calibration is sometimes confused with adjustment of a measuring system, often mistakenly called self calibration, or with calibration verification (ISO 18113-1); NOTE 10: The process of testing and adjusting an instrument, kit, or test system to establish a correlation between the measurement response and the concentration or amount of the substance measured by the test procedure (modified from 42 CFR §493.2); NOTE 11: Calibration can also be described as the set of operations that establishes the relationship between measured signal and concentration based on calibration materials of known concentration; NOTE 12: Calibration is the set of operations that establish, under specified conditions, the relationship between reagent system/instrument response and the corresponding concentration/activity values of an analyte.


calibration

the set of operations that establish, under traceable conditions, the relationship between values indicated by a measuring instrument or measuring system for an established reference material and the corresponding value of a candidate reference material.


calibration

a process of testing and adjusting an instrument or test system to establish a correlation between the measurement response and the concentration or amount of the substance that is being measured by the test procedure (42 CFR § 493.2)

Project: POCT17, H26, H44, POCT13


calibration

the process of testing and adjustment of an instrument, kit, or test system to provide a known relationship between the measurement response and the value of the substance measured by the test procedure.

Project: GP26, QMS13


calibration curve

expression of the relation between indication and corresponding measured quantity value (JCGM 200:2012)

Project: H48, ISO IEC Guide 99, MM19

NOTE: A calibration curve expresses a one-to-one relation that does not supply a measurement result as it bears no information about the measurement uncertainty (JCGM 200:2012).


calibration curve

the graphical relationship between the readings obtained in an analytical process (eg, absorbance, voltage) and the amount of analyte in a calibrator;

Project: NRSCL8

NOTE: The relationship is often a straight line rather than some other form of curve.


calibration diagram

graphical expression of the relation between indication and corresponding measurement result (JCGM 200:2012)

Project: ISO IEC Guide 99

NOTE 1: A calibration diagram is the strip of the plane defined by the axis of the indication and the axis of measurement result, that represents the relation between an indication and a set of measured quantity values. A one-to-many relation is given, and the width of the strip for a given indication provides the instrumental measurementuncertainty (JCGM 200:2012); NOTE 2: Alternative expressions of the relation include a calibration curve and associated measurement uncertainty, a calibration table, or a set of functions (JCGM 200:2012); NOTE 3: This concept pertains to a calibration when the instrumental measurement uncertainty is large in comparison with the measurement uncertainties associated with the quantity values of measurement standards (JCGM 200:2012).


calibration hierarchy

sequence of calibrations from a reference to the final measuring system, where the outcome of each calibration depends on the outcome of the previous calibration (JCGM 200:2012)

Project: ISO IEC Guide 99

NOTE 1: Measurement uncertainty necessarily increases along the sequence of calibrations (JCGM 200:2012); NOTE 2: The elements of a calibration hierarchy are one or more measurement standards and measuring systems operated according to measurement procedures (JCGM 200:2012); NOTE 3: For this definition, the ‘reference’ can be a definition of a measurement unit through its practicalrealization, or a measurement procedure, or a measurement standard (JCGM 200:2012); NOTE 4: A comparison between two measurement standards may be viewed as a calibration if the comparison is used to check and, if necessary, correctthe quantity value and measurement uncertainty attributed to one of the measurement standards (JCGM 200:2012).


calibration interval

a period of time or series of measurements during which calibration can be expected to remain stable within specified and documented limit (U.S. CFR 493 February 28, 1992)


calibration interval

period of time following a calibration during which an IVD reagent under specified conditions demonstrates apparent change in measurand content within the allowable drift limit and all stability-related criteria are met.

Project: EP25


calibration line

the graphic relationship (typically linear) between the clotting time in seconds and the INR of certified plasmas.

Project: H54, H47


calibration material

a material or device of known or assigned quantitative characteristics (eg, concentration, activity, intensity, reactivity, responsiveness) used to adjust the output of a measurement procedure or to compare the response obtained with the response of a test specimen and/or sample

Project: QMS24, NRSCL08, QMS13

NOTE 1: The guideline document for the HCFA regulations in the United States (Appendix C, Survey procedures, PC122) defines a calibration material as "a solution which has a known amount of analyte weighed in or has a value determined by repetitive testing using a reference or definitive test method"; NOTE 2: The quantities of the analytes of interest in the calibration material are known within limits ascertained during its preparation and may be used to establish the relationship of an analytical method’s response to the characteristic measured for all methods or restricted to some; NOTE 3: Calibration materials with different amounts of analytes may be used to establish a calibration or response "curve" over a range of interest; NOTE 4: The term "standard," commonly used in clinical laboratory protocols and having there a meaning as described here, has a specific and different meaning in the U.S. CFR 493, February 28, 1992; NOTE 5: The terms "primary" and "secondary standard" are used by WHO and ISO to refer to calibration materials; NOTE 6: The calibration material must be traceable to a national or international reference preparation or reference material when these are available.


calibration material

a material (eg, solution) or device of known quantitative/qualitative characteristics (eg, concentration, activity, intensity, reactivity) used to calibrate, graduate, or adjust a measurement procedure or to compare the response obtained with the response of a test specimen/sample

Project: I/LA20

NOTE 1: The quantities of the analytes of interest in the calibration material are known within limits ascertained during its preparation and may be used to establish the relationship of an analytical method’s response to the characteristic measured for all methods or restricted to some; NOTE 2: The calibration material must be traceable to a national or international reference preparation or reference material when these are available; NOTE 3: Calibration materials with different amounts of analytes may be used to establish a calibration or response “curve” over a range of interest; NOTE 4: The terms “primary” and “secondary standard” are used by the World Health Organization and the International Organization for Standardization to refer to calibration materials; NOTE 5: See calibrator.


calibration material

a material (eg, solution) or device of known quantitative/qualitative characteristics (eg, concentration, activity, intensity, reactivity) used to calibrate, graduate, or adjust a measurement procedure or to compare the response obtained with the response of a test specimen/sample.

Project: ILA34


calibration procedures

refer to the methods used to translate a device response measurement into a concentration, activity, or other outcome measurement. Calibration usually involves measurement of the device response in relation to special samples of known values called calibrators

Project: MM06


calibration standard

solution, prepared from reference material, that is used to calibrate the instrument response with respect to measurand concentration;

Project: C40

NOTE: There is no ISO term for calibration standard. In ISO terminology, it would be called a reference material used for calibration.


calibration transfer protocol

detailed description for assigning a value of a quantity to a reference material using a specified sequence of measurement procedures calibrated by higher-order reference materials for the same type of quantity (ISO 17511)

Project: X5


calibration transfer protocol transfer protocol

detailed description for assigning a value of a quantity to a reference material using a specified sequence of measurement procedures calibrated by higher-order reference materials for the same type of quantity (ISO 17511)

Project: ISO 17511


calibration verification

confirmation that stated trueness claims for an IVD measuring system are achieved (ISO 18113-1)

Project: ISO 18113-1, QMS13

NOTE 1: Calibration verification requires reference materials with assigned values at concentrations appropriate for the intended use (ISO 18113-1); NOTE 2: Calibration verification is sometimes confused with calibration, linearity verification or routine control procedures (ISO 18113-1).


calibration verification

the assaying of materials of known concentration in the same manner as patient samples to substantiate the instrument or test system's calibration throughout the reportable range for patient test results

Project: MM06, POCT04, POCT09, H26


calibrator

measurement standard used in calibration (JCGM 200:2012)

Project: H48, POCT04, QMS24, I/LA20, ISO IEC Guide 99, C34, H26, MM06, NBS05, C40

NOTE 1: The term "calibrator" is only used in certain fields (JCGM 200:2012); NOTE 2: In NBS05, a material or device of known or assigned quantitative characteristics (eg, concentration, activity, intensity, reactivity, responsiveness) used to adjust the output of a measurement procedure or to compare the response obtained with the response of a test specimen and/or sample; NOTE 3: The quantities of the analytes of interest in the calibration material are known; NOTE 4: Calibration materials with different amounts of analytes may be used to establish a calibration or response “curve” over a range of interest; NOTE 5: an instance in which the testing procedure is performed by a health care provider for an individual or individual; NOTE 6: Calibrators with different quantities or analytes may be used to establish a quantity/response "curve" over a range of interest.


calibrator

a material (eg, solution) or device with known quantitative/qualitative characteristics (eg, concentration, activity, intensity, reactivity) used to calibrate, graduate, or adjust a measurement procedure (POCT04);

NOTE 1: The quantities of the analytes of interest in the calibrator are known (POCT04); NOTE 2: Calibrators with different quantities or analytes may be used to establish a quantity/response “curve” over a range of interest (POCT04).


calibrator

reference material whose value is used for the independent variable in a calibration function (ISO 17511)

Project: ISO 17511, I/LA23


calibrator

measurement standard used in the calibration of an IVD instrument or system (adapted from JCGM 200:2012)

Project: ISO 18113-1


calibrator

substance, material, or article intended to be used in the calibration of an IVD medical device (modified from EN 375).

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3


calibrator

See calibration material.


calibrator

a reference material (eg, solution, suspension) or device of known quantitative/qualitative characteristics (eg, concentration, activity, intensity, reactivity) used to calibrate, graduate, or adjust a measurement procedure or to compare the response obtained with the response of a test specimen/sample;

Project: H26, MM06

NOTE 1: The quantities of the measurands of interest in the calibrator are known within limits ascertained during its preparation and may be used to establish the relationship of a measurement procedure’s response to the characteristic measured for all methods or restricted to some. The calibrator must be traceable (see CLSI document H15) to a national or international reference preparation or reference material when these are available. Calibrators with different quantities of measurands may be used to establish a quantity/response curve over a range of interest, although most hematology analyzers use a single-point calibration; NOTE 2: Calibrators can be used internal (within the same tube) or external (in another tube) to the specimen. In such cases, within this guideline, they are referred to as internal calibrators or external calibrators.


calibrator

measurement standard used in the calibration of an IVD instrument or system (ISO 18113-1)

Project: ISO DIS 18113-1


calibrator

See calibration material.

Project: ILA34


calorie

(C) the amount of heat it takes to raise the temperature of 1000 g or 1 kg of water one degree Centigrade;

Project: GP28

NOTE: A calorie is actually a kilocalorie or 1000 calories.


calorie

(C) The amount of heat it takes to raise the temperature of 1 g of water 1 degree centigrade;

Project: GP28

NOTE: The cal/min is the unit of heat per minute.


candidate measurement procedure

measurement procedure for which the performance characteristics are being evaluated for suitability for clinical use

Project: EP21, EP27


capability

ability to deliver an intended outcome of an exercise with any combination of properly planned, organized, equipped, trained, and exercised personnel though the execution of plan documents.

Project: GP36


capacity

the maximum amount or number that can be received or contained (RHUD1.7CD)


capacity factor

fraction of a sample compound distributed into stationary phase divided by the fraction in mobile phase;

Project: C62

NOTE: It is also called retention factor, and symbolized as kʹ.


capillary

one of the minute blood vessels between the terminations of the arteries and the beginnings of the veins (RHUD1.7CD)

Project: GP48


capillary action

the net chemical and physical effects that cause a liquid to rise (be drawn up) into a narrow-bore tube (capillary tube) in the absence of an atmospheric pressure differential (Cf. H14, POL1/2).

Project: H14, POL1/2


capillary blood

blood obtained by skin puncture or incision that contains a mixture of undetermined proportions of blood from arterioles, venules, and interstitial and intracellular fluids

Project: GP42, GP39, GP34


capillary blood sample

blood collected after puncturing minute vessels that connect the arterioles and venules (ISO 17593)

Project: ISO 17593

NOTE: Often obtained by pricking a fingertip; capillary blood is usually collected without additives, such as anticoagulants or preservatives. Therefore, it is inherently unstable (ISO 17593).


capillary electrophoresis

(CE) an automated application of gel electrophoresis using glass capillaries;

Project: MM09

NOTE: Typically, CE is performed at a high voltage, and the separation is faster than other gel electrophoretic techniques. Separation is based on molecular size and, in some cases, on ion current flows.


capillary electrophoresis

electrophoretic technique in which DNA fragments are separated by size in a thin capillary filled with a viscous matrix;

Project: MM05

NOTE: Typically, capillary electrophoresis is performed at a high voltage, and the separation is faster than other gel electrophoretic techniques. Separation is based both on molecular size and in some cases on ion current flows.


capillary tube

a hollow cylindroid of sufficiently narrow internal diameter such that it brings about sufficient capillary action, when its tip is placed in a fluid specimen to enable collection of a sample for analysis.


capsule

a mucopolysaccharide material surrounding a cell.

Project: M54


capture by hybridization

a method of nucleic acid target enrichment by hybridization of template nucleic acids to complementary DNA sequences that are attached to a solid surface.

Project: MM09


capture microsphere calibrator

as used in this document, a microsphere that has been surface-labeled with a reagent, usually an antibody, that binds fluorochrome-labeled ligands.

Project: I/LA24


carbon dioxide

(CO2) a colorless, odorless, incombustible gas that is a primary product of aerobic metabolism and is found dissolved and chemically bound in blood and other tissues.

Project: NRSCL8


carboxyfluorescein succinimidyl ester

(CFSE) a cell-labeling fluorescent dye typically excited by a “blue” (488 nm) laser which, upon entering cells, covalently links to intracellular proteins;

Project: I/LA26

NOTE 1: The linkage is very stable and the dye, once linked to intracellular molecules, does not leak out of cells or transfer to other cells; NOTE 2: Due to the progressive halving of the amount of dye with each successive cell division, and the ability to detect and measure this reduced fluorescence by flow cytometry, CFSE measurements have been used as a marker of proliferation; NOTE 3: CSFE is excited at approximately 494 nm with an emission maximum at 521 nm.


carboxyhemoglobin

(COHb) a dyshemoglobin with heme groups that are covalently bonded to carbon monoxide.

Project: C25, C41


carcinogen

any substance capable of causing malignant tumors in humans or animals;

Project: GP05

NOTE: See the Agency for Toxic Substance and Disease Registry’s (ATSDR’s) Annual Report on Carcinogens for current information on carcinogens.


cardiopulmonary bypass

(CPB) a procedure used to sustain organ perfusion with oxygenated blood during cardiac surgery

Project: POCT14


carnitine

carnitine is a seven-carbon molecule with three important functional groups: a quaternary ammonium functionality, a carboxylic group, and a secondary alcohol

Project: NBS04

NOTE: See acylcarnitine.


carnitine and acylcarnitines

Carnitine is a five-carbon molecule with three important functional groups: a quaternary ammonium functionality, a carboxylic group, and a secondary alcohol. Carnitine esters, known as acylcarnitines, are derived by conjugation of fatty acids and carnitine through the alcohol group. The fatty acid attached to carnitine reflects the composition of fatty acids within the mitochondria. The fatty acids are typically between two and 20 carbons, may be saturated or unsaturated, and may contain a hydroxyl or carboxylic acid group. The elemental composition of the fatty acid is important in determining the mass of the acylcarnitine and, hence, its identification. Acylcarnitines function as biomarkers for a number of inherited metabolic disorders (fatty acid oxidation disorders and organic acidemias).

NOTE: Throughout NBS04, the acylcarnitine species are referred to by their acyl chain carbon lengths (eg, octanoylcarnitine is referred to as C8). See the figures in Appendix I for the chemical structures of carnitine and acylcarnitines.


carrier

a molecule to which a microbial polysaccharide is chemically linked for the purpose of eliciting a T-cell-dependent immune response and thus modifying the humoral immune response to the polysaccharide


carrier

See specimen carrier.

Project: AUTO02, AUTO12


carrier (operator)

individual or organization engaged in the commercial transportation of goods.

Project: M29


carrier protein

a protein to which a specific ligand or hapten is conjugated (Cf. DI1).

Project: DI01


carrier screening

the identification of asymptomatic individuals of both sexes who are heterozygous for a common recessive disorder or females heterozygous for an X-linked recessive disorder and at risk to have an affected child.

Project: MM19


carryover

unintended contamination of a sample undergoing IVD examination with material from a previous sample (ISO/DIS 18113)

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3


carryover

the discrete amount of reagent or analyte carried by the measuring system from one test into subsequent test(s), thereby erroneously affecting test results.

Project: EP10, H44, H56, ILA33


carryover

process by which material is introduced into a reaction mixture to which it does not belong (ISO/DIS 18113-1);

Project: ISO DIS 18113-1

EXAMPLE: Part of a sample, reagent, diluent or wash solution that is transferred from one container, or from one reaction mixture, to another one (ISO/DIS 18113-1).
NOTE 1: Carryover can be either unidirectional or bidirectional (ISO/DIS 18113-1).
NOTE 2 Adapted from: IUPAC, Compendium of Analytical Nomenclature, 3rd edition (1998); Inczedy J, Lengyel T, Ure AM, eds.


cartridge

one type of unit-use device containing the components necessary to perform a test, including sensors, reagents, and calibration materials. A cartridge typically requires a meter to read signals and report results

Project: POCT04, POCT07


cascade reporting

strategy of reporting antimicrobial susceptibility test results in which secondary (eg, broader spectrum, more costly) agents may only be reported if an organism is resistant to primary agents within a particular drug class;

Project: M39

NOTE: Cascade reporting is one type of selective reporting).


case-control study

type of observational study design in which determination of outcome precedes determination of exposure

Project: GP45

NOTE 1: In this study design, the relationship of an attribute of subjects (or their environment) to the occurrence of a disease or other outcome of interest is examined by comparing a group of persons having this outcome (cases) with a suitable control (comparison, reference) group. The two groups are compared with respect to how frequently the attribute is present, or if quantitative, the levels of the attribute in each of the two groups. In other words, the past history of exposure to a suspected risk factor is compared between "cases" and "controls." The controls are persons who resemble the cases in such respects as age and sex, but do not have the disease or outcome of interest; NOTE 2: This study design starts after the occurrence of the outcome and looks back to the postulated causal factors. Cases and controls may be accumulated either retrospectively (i.e., from among subjects whose outcome and exposure status are already known) or prospectively (i.e., as each new case is determined, it is entered into the study).


case-finding

the performance of tests on an opportunistic basis when an individual presents to the health care system with a complaint unrelated to the tests performed

Project: ISO 15196, ISO TR 15196

EXAMPLE: Investigations ordered as part of routine "healthy checkups" and may employ screening tests. 


casework

premanufactured cabinet/countertop systems

Project: QMS04


casual glucose

See nonfasting glucose.

Project: POCT13


casualty

victim of an accident or disaster, usually referring to both deceased and living victims;

Project: GP36

NOTE: To be distinguished from “fatality.”


catalyst

a substance that increases the kinetics of a chemical reaction without being consumed in the reaction

Project: GP40


catalytic activity

(ZE) property of a component corresponding to the catalyzed substance rate of conversion of a specified chemical reaction, in a specified measurement system (ISO 18153)

Project: ISO 18153

NOTE 1: Adapted from IUPAC/IFCC 1995:9.101.3 (ISO 18153); NOTE 2: In this standard, the "component" is an enzyme (ISO 18153); NOTE 3: The quantity "catalytic activity" relates to an amount of active enzyme, not its concentration; see catalytic-activity concentration (ISO 18153); NOTE 4: The coherent derived SI unit is "mole per second" (mol s-1), also called "katal" (kat) (modified from ISO 18153); NOTE 5: The measurement procedure is an essential element of the definition of the measurand (ISO 18153); NOTE 6: In many instances, instead of the conversion rate of the substrate ascribed in the short name of the enzyme analyte, e.g., "creatine" in "creatine kinase," the conversion rate of an indicator substance as substrate of a combined reaction, e.g., NADH, is measured. Then the measurand should be defined as "catalytic activity of the enzyme as measured by the conversion rate of an indicator substance in a specified system according to a given measurement procedure," e.g., "catalytic activity of creatine kinase as measured by the rate of conversion of NADP in the IFCC reference procedure in human serum" (ISO 18153).


catalytic activity concentration

(bE) catalytic activity of a component divided by volume of the original system (ISO 18153)

Project: ISO 18153

NOTE 1: Adapted from IUPAC/IFCC 1995:9.104.2 (ISO 18153); NOTE 2: The coherent derived SI unit is "mole per second cubic metre" (mol s-1 m-3 = kat m-3). In laboratory medicine, the unit of volume may be chosen to be "litre" (l) (modified from ISO 18153); NOTE 3: In ISO 18153, the "component" is an enzyme and the "original system" can be, e.g., the plasma of a blood sample (ISO 18153).


catalytic concentration

See catalytic activity concentration.


category 1 laboratory

a laboratory that accepts specimens for anaerobic culture but only detects the presence of anaerobes;

Project: M56

NOTE: Anaerobes are referred to another laboratory for identification and antimicrobial susceptibility testing.


category 2 laboratory

a laboratory that screens for the major anaerobic groups;

Project: M56

NOTE: Definitive identification and antimicrobial susceptibility testing are performed in a reference laboratory.


category 3 laboratory

a laboratory that can identify anaerobes to genus and species level using phenotypic and enzymatic tests;

Project: M56

NOTE: It may perform some antimicrobial susceptibility testing.


category 4 laboratory

a laboratory that provides final identifications using 16s ribosomal RNA gene sequencing or matrix-assisted laser desorption/ionization time-of-flight technology;

Project: M56

NOTE: It may perform quantitative antimicrobial susceptibility testing .


Category A, infectious substance

see infectious substance, Category A.

Project: M29


category agreement

(CA) agreement of SIR results between a breakpoint test or an MIC test and the reference method (ISO 20776-1); Another representation of the concept: NCA × 100/N,whereNCA is the number of bacterial isolates with the same SIR category as the reference method category result; N is the total number of bacterial isolates tested (ISO 20776-2)

Project: ISO 20776-2

NOTE: The overall CA is expressed as a percentage (ISO 20776-2).


category agreement

agreement of susceptible, intermediate, susceptible-dose dependent, and resistant results between a breakpoint test or a minimal inhibitory concentration test and the reference method (modified from ISO 20776-2)

Project: M52

NOTE: Another representation of the concept: NCA • 100/N where: NCA is the number of microbial isolates with the same susceptible, intermediate, susceptible-dose dependent, and resistant category as the reference or comparator method category result; N is the total number of microbial isolates tested (modified from ISO 20776-2).


Category B, biological substance

see biological substance, Category B.

Project: M29


catheter

a hollow tube of rubber or plastic, passed through the urethra for the purpose of collecting urine directly from the urinary bladder (CLSI document GP16).

Project: GP16


catheter specimen

a urine specimen collected from a catheter placed into the bladder through the urethra.


cathode

negatively charged conductor that is the source of electrons in an electrical device.

Project: GP28


cation exchange resin

an ion-exchange resin with immobilized negatively charged exchange sites, which can bind positively charged ionized species

Project: GP40


CD4 and CD8 T-cells

the two major classes of mature T-cells, which are marked by the usually mutually exclusive expression of the molecules CD4 and CD8;

Project: I/LA26

NOTE 1: CD4 T-cells typically recognize peptides bound to Class II major histocompatibility protein complexes and provide help to B-cells, macrophages, dendritic cells, and CD8 T-cells; NOTE 2: CD8 T-cells typically recognize peptides bound to Class I major histocompatibility protein complexes and are best known for their cytotoxic function.


CE marking

symbolizes the conformity of the product with the applicable European Community requirements imposed on the manufacturer. The CE marking affixed to products is a declaration by the person responsible that the product conforms to all applicable European Community provisions, and the appropriate conformity assessment procedures have been completed (see Guide to the Implementation of Directives Based on New Approach and Global Approach).

Project: H59, M53, MM19, NBS05, MM01, MM07, MM22, MM03


CEF

a pool of 23 8-11-mer peptides representing conserved epitopes from cytomegalovirus, Epstein-Barr virus, and influenza virus (CEF peptide pool), restricted by common major histocompatibility complex Class I alleles.

Project: I/LA26


cell block

a paraffin section slide made from the centrifuged remains of a cytology specimen in fluid;

Project: MM23

NOTE: Cell blocks are made only when sufficient material remains in the container after preparation of cytology smears or thin-layer preparations.


cell culture

technique for growing cells in a laboratory setting


cell culture propagation

serial transfer of suspended cell culture cells (eg, derived from a trypsinized monolayer) to a fresh culture vessel containing growth medium

Project: M41


cell smear

tissue or cellular samples that are smeared across a glass microscope slide for subsequent staining and microscopic examination;

Project: MM23

NOTE: Cell cytology samples may also be prepared by centrifugation.


cellulose acetate electrophoresis

electrophoresis in which microporous cellulose acetate (strips or plates) is the support medium for the solutes and solvents (Cf. H8).


censored data

the situation in which measurement results are simply reported as greater than or less than an imposed threshold rather than expressed in quantitative units;

Project: EP17

NOTE: For example, a result is known to be less than a stated limit but the actual result value is not available.


central laboratory

for CLSI document POCT07, a term chosen to conceptualize what is meant by the central, core, or main clinical laboratory setting to differentiate it from the point-of-care setting;

Project: POCT07

NOTE: See clinical laboratory.


centrifugation

separation of solids from liquids using rotational forces

Project: QMS04


centrifugation phase

the time period when the specimen is inside the centrifuge

Project: GP44


centrifugation tube

a glass or plastic tube in which urine is centrifuged for the purpose of preparing sediment for microscopic evaluation (CLSI document GP16);

Project: GP16

NOTE: Supernatant may also be tested when formed elements interfere with some chemical assays (CLSI document GP16).


cerebrospinal fluid

the fluid in the ventricles of the brain, between the arachnoid and th pia mater, and surrounding the spinal cord.

Project: C49


cerebrospinal fluid

fluid within the ventricles of the brain and the subarachnoid space.

Project: H56


certificate

(digital certificate) a certificate document in the form of a digital data object (a data object used by a computer) to which is appended a computed digital signature value that depends on the data object. (RFC 2828)

Project: AUTO09


Certificate of Analysis

(COA) document provided by the manufacturer stating that the released product meets all Quality System Regulation (QSR) requirements and quality control specifications;

Project: M50, C53

NOTE: COAs apply to individual lots of the product (ie, lot-specific).


Certificate of Compliance

(COC) document provided by the manufacturer stating that the product meets all Quality System Regulation (QSR) requirements and quality control specifications;

Project: M50

NOTE: COCs apply to all lots of the product (ie, product-specific).


certificate revocation list

(CRL) a data structure that enumerates digital certificates that have been invalidated by their issuer prior to when they were scheduled to expire. (RFC 2828)

Project: AUTO09


certification

a written statement by an authorized body that a product, production plant, or laboratory meets certain specifications or requirements (WHO-BS 95/1793)

Project: MM19

NOTE: Procedure by which a third party gives written assurance that a service conforms to specified requirements.


certification

the process of proving to government agencies, or other organizations, that the commissioned laboratory meets their specific safety or performance requirements

Project: QMS04


certification

process by which an external organization gives written assurance that a service or person conforms to specified requirements

Project: QMS21, QMS25, GP48, QMS17, QMS01, QMS14, QMS15, QMS20, GP23


certification authority

(CA) an entity that issues digital certificates (especially X.509 certificates) and vouches for the binding between the data items in a certificate (RFC 2828)

Project: AUTO09


certified plasmas

normal or abnormal plasma samples assigned a PT/INR value by a manufacturer or reference center, using a manual method based on a WHO accepted protocol determined against an appropriate thromboplastin IRP (or manufacturer or standard reference reagent) that has been calibrated against the appropriate WHO standard in a multicenter study (ie, a minimum of three laboratories for a primary standard and two laboratories for a secondary standard) (H54).

Project: H54, H47


certified reference material

(CRM) reference material, accompanied by documentation issued by an authoritative body and providing one or more specified property valueswith associated uncertainties and traceabilities, using valid procedures (JCGM 200:2012)

Project: H48, JCGM 200:2012, MM06, I/LA28, EP29, MM20, C40, C62

EXAMPLE: Human serum with assigned quantity value for the concentration of cholesterol and associated measurement uncertainty stated in an accompanying certificate, used as a calibrator or measurement trueness control material (JCGM 200:2012); NOTE 1: ‘Documentation’ is given in the form of a ‘certificate’ (see ISO Guide 31:2000) (JCGM 200:2012); NOTE 2: Procedures for the production and certification of certified reference materials are given, eg, in ISO Guide 34 and ISO Guide 35 (JCGM 200:2012); NOTE 3: In this definition, "uncertainty" covers both ‘measurement uncertainty’ and ‘uncertainty associated with the value of a nominal property,’ such as for identity and sequence. "Traceability" covers both ‘metrological traceability of a quantity value’ and ‘traceability of a nominal property value’ (JCGM 200:2012); NOTE 4: Specified quantity values of certified reference materials require metrological traceability with associated measurement uncertainty (Accred Qual Assur. 2006;10:576-578); NOTE 5: ISO/REMCO has an analogous definition (Accred Qual Assur. 2006;10:576-578) but uses the modifiers ‘metrological’ and ‘metrologically’ to refer to both quantity and nominal property (JCGM 200:2012).


certified reference material

(CRM) reference material characterized by a metrologically valid procedure for one or more specified properties, accompanied by a reference material certificate that provides the value of the specified property, its associated uncertainty, and a statement of metrological traceability (ISO Guide 30)

NOTE 1: The concept of value includes qualitative attributes such as identity or sequence. Uncertainties for such attributes may be expressed as probabilities (modified from ISO Guide 30); NOTE 2: Metrologically valid procedures for the production and certification of reference materials are given in, among others, ISO Guides 34 and 35 (ISO Guide 30); NOTE 3: ISO Guide 31 gives guidance on the contents of reference material certificates (ISO Guide 30).


certified reference material

(CRM) reference material, accompanied by a certificate, one or more of whose property values are certified by a procedure which establishes metrological traceability to an accurate realization of the unit in which the property values are expressed, and for which each certified value is accompanied by an uncertainty at a stated level of confidence (ISO 17511)

Project: X05, ISO 17511, MM17


certified reference material

(CRM) a reference material that has one or more values certified by a technically valid procedure and is accompanied by, or is traceable to, a certificate or other document that is issued by a certifying body

Project: H15

NOTE: The term "Standard Reference Material" (SRM) is the name of a certified reference material (CRM), which is the trademark name of a certified reference material that has been certified and is distributed by the National Institute of Standards and Technology (NIST), a U.S. government agency formerly known as the National Bureau of Standards (NBS).


certified reference material

(CRM) reference material, accompanied by documentation issued by an authoritative body and referring to valid procedures used to obtain a specified property value with uncertainty and traceability (ISO 15194)

Project: ISO 15194

EXAMPLE: Human serum containing cholesterol with assigned quantity value and associated measurement uncertainty stated in an accompanying certificate, used as calibrator or trueness control material (ISO 15194); NOTE 1: In this definition, uncertainty covers both "measurement uncertainty" and "uncertainty of nominal value," such as for identity and sequence, expressed as probabilities. Traceability covers both "metrological traceability" of a quantity value and "traceability of nominal value" (ISO 15194); NOTE 2: "Certified reference material" is a specific concept under "reference material" (ISO 15194).


certified reference material CRM

(CRM) reference material, accompanied by a certificate, one or more of whose property values are certified by a procedure which establishes traceability to an accurate realization of the unit in which the property values are expressed, and for which each certified value is accompanied by an uncertainty at a stated level of confidence (ISO Guide 30);

Project: ISO 15195

NOTE 1: The definition of a "reference material certificate" is given in Section 4.2 of ISO Guide 30:1992; NOTE 2: CRMs are generally prepared in batches for which the property values are determined within stated uncertainty limits by measurements on samples representative of the whole batch; NOTE 3:The certified properties of certified reference materials are sometimes conveniently and reliably realized when the material is incorporated into a specially fabricated device, e.g., a substance of known triple-point into a triple-point cell, a glass of known optical density into a transmission filter, spheres of uniform particle size mounted on a microscope slide. Such devices may also be considered as CRMS; NOTE 4: All CRMs lie within the definition of "measurement standards" or "etalons" given in the "International Vocabulary of Basic and General Terms in Metrology (VIM)"; NOTE 5: Some RMs and CRMs have properties which, because they cannot be correlated with an established chemical structure or for other reasons, cannot be determined by exactly defined physical and chemical measurement methods. Such materials include certain biological materials such as vaccines to which an International unit has been assigned by the World Health Organization; NOTE 6: A material that is used as a standard or reference and whose assigned value is traceable to a reference measurement system. An accompanying certificate states the measurand value and the measurement uncertainty (MM06).


certified value

value, assigned to a property of a reference material that is accompanied by an uncertainty statement and a statement of metrological traceability, identified as such in the reference material certificate (ISO Guide 30)


cestode

tapeworm

Project: M28


CFTR-related metabolic syndrome

an asymptomatic, hypertrypsinogenemic infant with either a sweat chloride concentration of 30–59 mmol/L if age < 6 months, or 40–59 mmol/L if age ≥ 6 months, on at least two occasions, and completed expanded genetic analysis with fewer than two CF disease–causing mutations or a sweat chloride concentration < 30 mmol/L if age < 6 months, or < 40 mmol/L if age ≥ 6 months, and two CFTR mutations, in trans, of which no more than one is known to be CF disease–causing

Project: NBS05


CGM sensor output signal

the output signal from a CGM sensor that contains both glucose-specific information and noise;

Project: POCT05

NOTE 1: Noise is a change in the output signal unrelated to a change in the glucose concentration. The glucose-specific signal and the noise signal change independently over time (POCT05); NOTE 2: Sensor performance is modeled under steady state in vitro and in vivo conditions to develop an algorithm that distinguishes the glucose-specific signal from the noise and the drift (POCT05); NOTE 3: Sensor drift is a progressive and gradual change in deviation between sensor reading and reference value over time. Drift is typically caused by a change in the sensing system or changes at the interface between the sensing surface and the biological tissue (POCT05); NOTE 4: Drift that occurs slowly, in a characteristic fashion, can be managed by recalibration of the in vivo sensor to a reference blood glucose measurement (POCT05); NOTE 5: Noise is a change in the sensor output signal unrelated to a change in the glucose concentration. Chemical and physical changes external to the sensor (tissue fluid interface with sensor), and internal to the sensor (transducer and electrode foiling), cause a change in the output signal unrelated to glucose. The sensor noise level is affected by the bandwidth of the sensor system and therefore, noise measurements and specifications should include references to the system bandwidth. Lowering the system bandwidth tends to decrease the noise level at the cost of a slower system response (POCT05); NOTE 6: The output signal from two or more CGM sensors (in vivo array) can be analyzed to optimize glucose measurement accuracy and precision related to direction of change, rate of change, and absolute value. Processing multiple output signals can decrease noise and compensate for drift (POCT05).


CGM sensor run-in time

the time from initial sensor insertion until initial calibration;

Project: POCT05

NOTE 1: The run-in time is caused by unstable chemical/physical conditions around the sensor and changes internal to the sensor. Needle-type and dialysis type CGM sensors damage blood vessels, extracellular matrix, and cells during subcutaneous tissue insertion. The coagulation, immune, and inflammatory systems may be activated. The in vivo sensor exhibits frequent changes in noise and drift (POCT05); NOTE 2: Manufacturers have to take appropriate measures to make sure sensor signal is stable enough for the initial calibration and/or recalibration using an appropriate sample (POCT05).


CH50 unit

in a complement fixation assay, the dilution of a serum that will lyse 50% of sensitized sheep red cells; used as a measure of specific antigen, antibody, or immune complex concentration (Cf. DI1)

Project: Dl01


CH50 unit

in a complement fixation assay, the dilution of a serum that will lyse 50% of sensitized sheep red blood cells; used as a measure of specific antigen, antibody, or immune complex concentration.

Project: DI01


chain of custody

a forensic document that unequivocally identifies the donor of a specimen and tracks its handling from the time of collection to the completion of testing and disposal

Project: C52

NOTE: The chain of custody must not be broken and must account for the history of the specimen with no gaps. The chain of custody must be retained in the laboratory for a specified period of time after completion of testing and the reporting of results.


challenge

1) for quantitative tests, an assessment of the amount of substance or analyte/measurand present or measured in a sample; 2) for qualitative tests, the determination of the presence or the absence of an analyte/measurand, organism, or substance in a sample (modified from 42 CFR §493.2)

Project: QMS24, MM14


challenge

for quantitative tests, an assessment of the amount of substance or analyte present or measured in a sample


chance

random error

Project: GP45


chancre

a sore or ulcer located at the initial point of entry of a pathogen.

Project: M54


change order

written order to the contractor to change something that was previously shown in the approved drawings or specifications

Project: QMS04


chaotrope

a chemical denaturing agent that solubilizes protein samples and lowers the melting temperature of double-stranded nucleic acids.

Project: MM03


character

1) the smallest abstract element of a writing system or script;

Project: AUTO01, AUTO02, AUTO07, AUTO03, AUTO12

NOTE 1: A character refers to an abstract idea rather than to a specific shape; 2) a code element; 3) a member of a set of elements upon which agreement has been reached and that is used for the organization, control, or representation of information; NOTE 2: Characters may be letters, digits, punctuation marks, or other symbols, often represented in the form of spatial arrangement of adjacent or connected strokes or in the form of other physical conditions in the data media; 4) a letter, digit, or other symbol that is used as part of the organization, control, or representation of data; NOTE 3: A character is often in the form of a spatial arrangement of adjacent or connected strokes (ASTM F149); 5) in data transmission, one of a set of elementary symbols that normally include both alpha and numeric codes plus punctuation marks and any other symbol that may be read, stored, or written and is used for organization, control, or representation of data; 6) in computers, a letter, digit, or other symbol used to represent information (IEEE 610.1, 610.5, 610.12).


characterization

determination of one or more physical, chemical, or biological parameters of a material, or of a product and/or preparation, that are relevant to its general use


characterization

(of a reference material) process of determining the property values of a reference material, as part of the certification process (ISO Guide 35)

Project: C53

NOTE 1: The characterization process provides the values for the properties to be quantified (ISO Guide 35); NOTE 2: In batch certifications, the characterization refers to the property values of the batch (ISO Guide 35).


characterization

(of a reference material) determination of the property values or attributes of a reference material, as part of the production process (ISO Guide 30)


Charcot Leyden crystals

slender crystals that are formed from the breakdown products of eosinophils; shaped like double, elongated pyramids with pointed ends; can be found in feces, sputum, and tissues; indicates an immune response that may or may not be related to a parasitic infection.

Project: M28


charges

the price of a service or amount billed an individual or third party, which may or may not be equal or even proportional to service costs

Project: GP45


charter

the granting of authority or rights, stating that the grantor formally recognizes the prerogative of the recipient to exercise the rights specified.

Project: QMS14


charter

(n) document or authorization from the organization’s leadership that outlines and communicates the principles, scope, rights, and privileges for establishing a project, committee, function, etc.

Project: QMS15


checklist

tool for organizing and ensuring that all important actions in a process or steps in a procedure are taken into consideration or acted upon (modified from ISO 19011)

Project: QMS15


checklist

tool for organizing and ensuring that all important steps or actions in a process are taken into consideration or acted upon.

Project: QMS06


chemical ionization

(CI) an ionization process that leads to new ionized species arising from the interaction between molecules and gas phase ions, formed specifically for the purpose (ie, as “reagent ions”) (CLSI document C50);

Project: C50

NOTE: CI spectra are simpler than electron ionization (EI) spectra and are often dominated by an intense protonated or adducted molecular ion (M+H) + with few or no fragment ions (CLSI document C50).


chemical ionization

(CI) the formation of new ionized species when gaseous molecules interact with ions;

Project: C43

NOTE: The process may involve transfer of an electron, a proton, or other charged species between the reactants. When positive ion results from chemical ionization (CI), the term may be used without qualification; when a negative ion results, the term "negative ion chemical ionization" can be substituted. Specifics relating to ionization should be given, eg, if negative ions are formed from sample molecules via resonance capture of thermal electrons generated in a CI source, this should be specified.


chemical waste

this category includes chemical waste that is regulated as hazardous waste, as well as unregulated chemical waste that poses a risk to health and to the environment;

Project: GP05

NOTE: Most chemical waste is regulated as hazardous waste. See hazardous waste.


chemiluminescence immunoassay

nonenzymatic chemical reaction that emits light, the amount of which can be related to the concentration of the analyte being measured.

Project: H59


chemiluminescent assay

an assay in which the signal is generated by a compound that emits light as the result of a chemical reaction.

Project: M53


chi square analysis

statistical analysis that compares true positives, true negatives, false positives, and false negatives to establish probability (r-value);

Project: ILA29

NOTE: The calculation can be used to compare methods, or to determine the strength of the relationship between test results and clinical outcomes, etc.


chimerism

when an organism has two or more different populations of genetically distinct cells;

Project: MM21

NOTE: In humans, this condition may be congenital or acquired through infusion of allogeneic hematopoietic cells during transplantation or transfusion.    


chimerism

a chimera is an organism that has two or more different populations of genetically distinct cells. In humans, this condition may be acquired through infusion of allogeneic hematopoietic cells during transplantation or transfusion.

Project: MM19


chip

See microchip.

Project: ILA29


chip reader

instrument that reads the microscopic spots on a microarray chip and determines if they are positive or negative.

Project: ILA29


chi-squared distribution

the {parametric} probability distribution of a continuous random variable that can take any value from zero to infinity (ISO 3534-1/93-1.39).

Project: ISO 3534


chlorhexidine gluconate

the digluconate salt of chlorhexidine (Dorland's Medical Dictionary);

Project: M47

NOTE: It is used as a topical agent for cleansing and disinfecting the skin.


chloridometer

a coulometric titrator used to measure chloride ion concentration.

Project: C34


cholesterol

a sterol, of the formula C27H46O7 found in blood plasma bound to lipoproteins as well as in other body tissues.


cholesterol effusion

as a subtype of pleural fluid, due to chronic pleural effusion with breakdown of inflammatory cell membranes into cholesterol crystals;

Project: C49

NOTE: This fluid can appear iridescent and is sometimes referred to as "pseudochylous."


chromatin

deep staining DNA containing portion of the nucleus (protozoa).

Project: M28


chromatoidal bar

deep-staining, bar-shaped, round, or splinter-shaped inclusions found in the cytoplasm of certain amoebae (Entamoeba spp.)

Project: M28


chromoblastomycosis

a cutaneous or subcutaneous infection caused by darkly pigmented fungi (eg, Phialophora, Fonsecaea) characterized by the presence of dematiaceous (phaeoid) sclerotic cells.

Project: M54


chromogen

(substrate) in Immunohistochemistry, a chromogen is used to localize bound antibody;

Project: I/LA28

NOTE: Chromogens are dissolved in a buffered substrate and when reacted with an appropriate enzyme, the substrate-chromogen produces a colored reaction product that specifically labels enzyme-linked immunoreactive substances in cells and tissues.


chromogenic agar

a differential agar growth medium for bacteria on which organisms of a particular species produce colonies of a unique color, which enhances their detection in clinical specimens that may contain multiple species of bacteria, eg, detection of methicillin-resistant Staphylococcus aureus in nasal swab specimens

Project: M55


chromogenic reagent

reagent that reacts with certain chemical groups present or induced in cells and tissues with the formation of a coloured compound in situ (ISO 19001) 

Project: ISO 19001

EXAMPLE: Diazonium salt, Schiff’s reagent (ISO 19001).


chromogenic substrate

a substrate that generates a colored product in an enzyme-catalyzed reaction (Cf. DI1).

Project: DI01, ILA29


chromosome

a single, large DNA molecule with its associated proteins that contains many genes and functions to store and transmit genetic information.

Project: MM02, MM10


chylothorax

as a subtype of pleural fluid, indicates injury to the thoracic (lymphatic)duct with release of fat droplets/chylomicrons into the pleural space.

Project: C49


ciphertext

data that has been transformed by encryption so that its semantic information content (i.e., its meaning) is no longer intelligible or directly available. (See: plaintext.) (RFC 2828)

Project: AUTO09


circadian variation

variations in physiological parameters, including blood analyte concentrations, which are related to cyclic events, i.e., time of day, season of the year, and ingestion of meals.

Project: C31


circulating cell-free tumor nucleic acid

free tumor DNA circulating in plasma of patients with cancer;

Project: MM23

NOTE: The origin may include necrotic tumor cells shed from tumor deposits, cellular fragments, tumor-derived exosomes, or lysis of circulating tumor cells in the bloodstream.


circulating tumor cell

cell that has detached from a primary tumor and circulates in the bloodstream;

Project: MM23

NOTE: These cells may constitute seeds for subsequent growth of additional tumors (metastasis) in different tissues.


cis/trans

these terms refer to the genetic phase (coupling/repulsion) of linked mutant alleles. In the cis phase, the individual is heterozygous at two neighboring loci and has the two mutations in question on the same chromosome. In the trans phase, the individual is heterozygous at two neighboring loci and has one of the two mutations in question on each of the two homologous chromosomes.

Project: MM19


citrate agar electrophoresis

electrophoresis in which the support medium is a citrate-containing agar gel.


civil air patrol

(CAP) an organization congressionally charted to assist the Air Force and federal, state, and local agencies with emergency assistance; operations include humanitarian/disaster missions employing general aviation aircraft for transportation of important cargo, including medical supplies and blood;

NOTE 1: The Air Force Auxiliary, Civil Air Patrol, is composed of 61,000 volunteers in 1,700 communities nationwide, organized as 52 Wings (states/territories) and Squadrons (local); NOTE 2: CAP contact may be provided in the LEOP in your community; NOTE 3: Information may be accessed at: www.capnhq.org.


clade

See subtype.

Project: M53


claimed microorganisms

microorganisms that have been validated by the manufacturer and approved/cleared for reporting by a regulatory organization

Project: M58


classical pathway

a series of sequential reactions among the components of complement, after their activation by antigen-antibody reactions or microbial products, in the order C1, C4, C2, C3, C5, C6, C7, C8, C9 (Cf. DI2).

Project: DI02


classification

organization of varied items into mutually exclusive but related classes (Business Dictionary)

Project: QMS04

NOTE: In the design process, fire rating, building type, biosafety type, and biological safety hoods are organized in this manner.


clean catch specimen

urine specimen that is collected from the middle of the urine stream after the first part of the flow has been voided (CLSI document GP16);

Project: GP16

NOTE 1: Also known as “midstream” urine; NOTE 2: The urinary tract naturally contains bacteria that can contaminate a urine sample. The clean-catch method is used to prevent these bacteria from getting into the urine sample (CLSI document GP16).


cleaning

process to remove any type of contamination, visible or not (ISO 15190)

Project: ISO 15190, POCT13


clearance

open space allowed adjacent to equipment to allow access for maintenance or airflow; open space allowed for staff to move freely and to accommodate disabled people

Project: QMS04


clerical error

an incorrect transcription or improper use of the reporting medium leading to an unacceptable PT result


CLIA '88

acronym for the Clinical Laboratory Improvement Amendments of 1988 (US CFR 493, February 28, 1992).


clinical breakpoint

1) a classification based on an in vitro response of an organism to an antimicrobial agent at levels corresponding to blood or tissue levels attainable with usually prescribed doses; 2) susceptible clinical breakpoint – a category that implies that an infection due to the isolate may be appropriately treated with the dosage of an antimicrobial agent recommended for that type of infection and infecting species, unless otherwise contraindicated; 3) intermediate clinical breakpoint – a category that includes isolates with antimicrobial agent minimal inhibitory concentrations (MICs) or minimal effective concentrations (MECs) that approach usually attainable blood and tissue levels and for which response rates may be lower than for susceptible isolates; 4) resistant clinical breakpoint – a category that includes resistant isolates that are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules or where clinical efficacy has not been reliable in treatment studies.

Project: M51


clinical consultant

an individual who is qualified to be a laboratory director who provides expertise regarding the appropriateness of the testing ordered and the interpretation of test results.

Project: MM19


clinical cutoff

a cutoff that is derived from any correlation there may be between clinical outcome and the minimal inhibitory concentrations of an antimicrobial agent(s) for the infecting pathogen(s)

Project: M23


clinical decision point

(critical value) decision limits determined on the basis of scientific and/or medical knowledge, often based on a medical condition


clinical evaluation

(of in vitro diagnostic devices) an investigation of the clinical performance characteristics of a new (or new indication for use of) in vitro diagnostic assay in controlled clinical settings (I/LA21);

Project: ILA21

NOTE 1: The term "clinical evaluation" (United States) is equivalent to the term "diagnostic evaluation" (Europe); NOTE 2: In Europe, as defined above, the term "diagnostic evaluation" is used. "Clinical evaluation" applies mostly to the evaluation of medical products, which are used on or in patients, or to clinical studies of drugs, under much more stringent conditions.


clinical exposure-response cutoff

(CER) the highest minimal inhibitory concentration value at which efficacy would be predicted in patients based on CER relationships for efficacy in infected patients and on human pharmacokinetics

Project: M23


clinical false-negative newborn screening result

a screen negative result reported in an affected newborn;

Project: NBS06

NOTE: As used in NBS06, a screen negative result of a newborn screening algorithm (based on the detection of T-cell receptor excision circles with a value above the cutoff) reported for a newborn later diagnosed with severe combined immunodeficiency.


clinical false-positive newborn screening result

a screen positive result reported in an unaffected newborn;

Project: NBS06

NOTE: As used in NBS06, the positive result of a newborn screening algorithm (based on the absence of T-cell receptor excision circles [TREC] or the detection of TREC at a value below the cutoff) that is obtained for a newborn who does not have severe combined immunodeficiency or severe T cell lymphopenia.


clinical feasibility

an evaluation performed using patient specimens to assess the potential application of a new assay to some clinical use (ILA21);

Project: ILA21

NOTE: Typically conducted by the sponsor, the evaluation may take place in a clinical setting or in the sponsor’s laboratory (ILA21).


clinical information system

(CIS) any information system or computer system database responsible for housing clinical patient information;

Project: POCT02

NOTE: Examples include hospital information systems (HIS), laboratory information systems (LIS), clinical data repository (CDR), and electronic medical records (EMR) (CLSI document POCT02).


Clinical Information System

(CIS) any health care information system (HIS) responsible for housing clinical information;

Project: POCT01

NOTE: Examples include laboratory information systems (LIS), clinical data repository (CDR), and electronic medical records (EMR).


clinical interpretative criteria (clinical breakpoints)

cutoff values designed to facilitate the prediction of clinical efficacy of a specified dose regimen, administered under specified conditions, for a specified target animal species, type of infection, and infecting organism. Clinical breakpoints provide numerical minimal inhibitory concentration (MIC) or zone diameter values that can be used to categorize an isolate as susceptible, intermediate, or resistant, as defined below. For example, for antimicrobial X with interpretive criteria of:

MIC (µg/mL) Zone Diameter (mm)
Susceptible ≤ 4 ≥ 20
Intermediate 8–16 15–19
Resistant ≥ 32 ≤ 14
“Susceptible breakpoint” is 4 µg/mL or less; or 20 mm. or more. “Resistant breakpoint” is 32 µg/mL or greater; or 14 mm or less.

Project: VET04


clinical interpretive criteria

(clinical breakpoint) numerical minimal inhibitory concentration (MIC) or zone diameter values used to indicate whether a clinical pathogen is susceptible, intermediate, or resistant to an antimicrobial.

Project: VET05


clinical investigator

a person under whose direction a clinical evaluation is conducted.

Project: ILA21, ILA18


clinical laboratories

laboratories that perform patient tests and are evaluated on their ability to do so by proficiency testing programs;

NOTE 1: In addition to fulfilling the clinical laboratory’s regulatory requirements, proficiency testing can be used as a proactive quality improvement tool; proficiency test results can also be misleading when the program or the testing materials are not appropriate to the test methodology used by the laboratory; NOTE 2: Knowledge of appropriate programs and their optimal use are of importance to these stakeholders.


clinical laboratory

See medical laboratory.


clinical laboratory

laboratory for the biological, microbiological, immunological, chemical, immunohematological, hematological, biophysical, cytological, pathological, genetic, or other examination of materials derived from the human body for the purpose of providing information for the diagnosis, management, prevention, and treatment of disease in, or assessment of the health of, human beings, and which may provide a consultant advisory service covering all aspects of laboratory investigation, including the interpretation of results and advice on further appropriate investigation (ISO 15189)

Project: POCT07, MM01, MM22

NOTE 1: These examinations also include procedures for determining, measuring, or otherwise describing the presence or absence of various substances or microorganisms (ISO 15189); NOTE 2: In some jurisdictions, the term "medical laboratory" is used.


clinical laboratory automation

the integration of laboratory personnel and preanalytical (preexamination), analytical (examination), and postanalytical (postexamination) processes and information systems.

Project: AUTO01, AUTO02, AUTO12


clinical laboratory automation systems

an assemblage of components that mechanically and electronically transfers, analyzes, and processes information and material related to clinical diagnostic testing of patient specimens, controls, calibrators, standards, and images

Project: AUTO01, AUTO02, AUTO12


clinical performance

the sum of all attributes that may be important for clinical use of results from a measurement procedure when applied to a specific intended use;

Project: EP19

NOTE: Performance specifications usually include diagnostic sensitivity and specificity, and other parameters of clinical usefulness.


clinical relevance

trait attributed to a genomic change or feature that is of medical significance for the diagnosis or management of a patient.

Project: MM09


clinical reportable range

(CRR) the range of analyte values that a method can report as a quantitative result, allowing for specimen dilution, concentration, or pretreatment used to extend the direct AMR (C50).

Project: C50, POCT09


clinical sensitivity

the proportion of subjects with a well-defined clinical disorder whose test values are positive or exceed a defined decision limit (ie, a positive result and identification of the patients who have a disease);

Project: MM01, GP10, ILA18, ILA21, H26, MM06, M53, MM05, MM20

NOTE 1: "Diagnostic sensitivity" is used in Europe and "clinical sensitivity" is used in the United States; NOTE 2: In Europe, the term "clinical" applies mostly to clinical studies of drugs, under much more stringent conditions; NOTE 3: Clinical sensitivity refers to the assay’s ability to detect subjects with the condition or disease; NOTE 4: It is the fraction of clinically true positives divided by the sum of clinically true-positive plus clinically false-negative classifications; NOTE 5: The clinical disorder must be defined by criteria independent of the test under consideration; NOTE 6: This term can also be defined as percent positivity in samples in which the target measurand (analyte) is known to be present (ie, derived from subjects with disease); NOTE 7: See seroconversion sensitivity.; NOTE 8: “Diagnostic sensitivity” is used outside of the United States and “clinical sensitivity” is used in the United States.


clinical sensitivity

as used in newborn screening (NBS), the proportion of clinical cases identified by the NBS algorithm among the total clinical cases in the screened population

Project: NBS07

NOTE 1: Clinical sensitivity refers to the assay’s ability to detect subjects with the condition or disease; NOTE 2: Clinical sensitivity is the fraction of clinically true positives divided by the sum of clinically true-positive plus clinically false-negative classifications; NOTE 3: As used in NBS07, clinical sensitivity refers to the ability of the NBS algorithm to identify individuals with any form of Pompe disease.


clinical sensitivity

the ability of a test under study to give a positive result for subjects having the disease/state in question;

Project: MM17, I/LA28

NOTE: See and use the definition of the preferred term diagnostic sensitivity.


clinical sensitivity

the proportion of patients with well-defined clinical disorders whose test values are positive or exceed a defined decision limit (eg, a positive result and identification of the patients who have a disease)

Project: NBS05, MM07

NOTE 1: The clinical disorder must be defined by criteria independent of the test under consideration; NOTE 2: The term clinical sensitivity (United States) is equivalent to diagnostic sensitivity (Europe); NOTE 3: Proportion of truly diseased persons in a screened population who are identified as diseased by the screening test. Sensitivity is a measure of the probability of correctly diagnosing a case, or the probability that any given case will be identified by the test. Infants with meconium ileus should be included in the calculation of sensitivity. Sensitivity = a / (a + c) where a = a true-positive result and c = a false-negative result.


clinical sensitivity

the ability of a test under study to give a positive result for subjects having the disease/state in question or the proportion of subjects with a well-defined clinical disorder whose test values are positive or exceed a defined decision limit (eg, a positive result and identification of the patients who have a disease);

Project: MM21, MM19, MM22

NOTE 1: "Diagnostic sensitivity" is used in Europe and "clinical sensitivity" is used in the United States; NOTE 2: In Europe, the term "clinical" applies mostly to clinical studies of drugs, under much more stringent conditions.


clinical sensitivity

as used in newborn screening (NBS), the proportion of clinical cases identified by the NBS algorithm among the total clinical cases in the screened population;

Project: NBS06

NOTE 1: Clinical sensitivity refers to the assay’s ability to detect subjects with the condition or disease; NOTE 2: It is the fraction of clinically true positives divided by the sum of clinically true-positive plus clinically false-negative classifications; NOTE 3: As used in NBS06, it refers to the ability of the NBS algorithm to identify subjects with severe combined immunodeficiency.


clinical significance

in the context of an evaluation of measurement procedure, the importance of an error due to its potential to alter a physician's diagnosis, treatment, or management of a patient.

Project: EP07, C56


clinical specificity

the proportion of subjects who do not have a specified clinical disorder whose test results are negative or within the defined decision limit;

Project: MM06, ILA21, MM01, MM22

NOTE 1: Clinical specificity refers to the assay’s ability to discriminate subjects who do not have the condition or disease from those who have the condition or disease; NOTE 2: It is the fraction of clinically true negative classifications divided by the sum of clinically true-negative plus clinically false-positive classifications; NOTE 3: In laboratory testing, the ability of a test to give a negative result for patients that do not have the disease or condition for which they are being tested; measured as the ratio of negative tests to the total number of tests in those that do not have the disease or condition; expressed as a percentage; NOTE 4: The term "clinical specificity" (United States) is equivalent to "diagnostic specificity" (Europe); NOTE 5: This term can also be defined as percent negativity in samples where the target analyte is known to be present (ie, derived from subjects without disease); NOTE 6: In Europe, the term "clinical" applies mostly to clinical studies of drugs.


clinical specificity

the proportion of patients who do not have a specified clinical disorder whose test results are negative or within the defined decision limit

Project: NBS05, MM07

NOTE 1: The term clinical specificity (United States) is equivalent to diagnostic specificity (Europe); NOTE 2: Proportion of truly nondiseased persons who are so identified by the screening test. It is a measure of the probability of correctly identifying a nondiseased person with a screening test. Specificity = d / (b + d) where b = a false-positive result and d = a true-negative result.


clinical specificity

the proportion of subjects without a well-defined clinical disorder whose test values are negative (eg, a negative result and identification of the patients who do not have a disease);

Project: M53

NOTE: Also referred to as diagnostic specificity.


clinical specificity

the ability of a test under study to give a negative result for subjects not having the disease in question;

Project: MM17, I/LA28, MM19, MM20

NOTE 1: See and use the definition of the preferred term diagnostic specificity. NOTE 2: Clinical specificity refers to the assay’s ability to discriminate subjects who do not have the condition or disease from those who have the condition or disease; NOTE 3: It is the fraction of clinically true-negative classifications divided by the sum of clinically true-negative plus clinically false-positive classifications; NOTE 4: In laboratory testing, the ability of a test to give a negative result for patients who do not have the disease or condition for which they are being tested. It is measured as the ratio of negative tests to the total number of tests in those who do not have the disease or condition, and expressed as a percentage; NOTE 5: The term "clinical specificity" (United States) is equivalent to "diagnostic specificity" (Europe).


clinical specimen

see patient specimen.

Project: M29


clinical state

a state of health or disease that has been defined by either a clinical definition or some other independent reference standard;

Project: EP24

NOTE: Examples of clinical states include “no disease found,” “disease 1” (where 1 represents the first clinical state under consideration), “disease 2” (where 2 represents the second clinical state under investigation), and so on.


clinical testing

diagnostic testing that is performed as part of a medical procedure

Project: C52

NOTE: Emergency departments, most hospital wards, and drug treatment programs are typical environments for this type of testing. In these situations, test results are needed to establish diagnoses, institute treatment, and monitor patient progress. Although a positive drug test result may lead to some type of legal action, clinical testing is not intended for forensic purposes.


clinical utility

value or benefit assigned to a particular outcome or state; diagnostic information that contributes to the identification of a particular condition or disease;

Project: MM17, I/LA28, MM19, MM20, MM22, MM23

NOTE: Clinical utility can encompass prognosis and monitoring response to therapy as well as diagnosis.


clinical validation

the process through which one shows that test results are clinically meaningful, ie, finding whether the test is able to detect or predict the disorder or condition of interest in targeted patient groups.

Project: EP19


clinical validity

the strength of the relationship between a test and a clinical characteristic of interest; typically expressed as clinical sensitivity and clinical specificity;

Project: MM09

NOTE: For genetic tests, the correlation between genotype and a clinical phenotype.


clinical validity

the accuracy with which a test predicts the presence or absence of a clinical condition or predisposition;

Project: MM17, MM19, MM20, MM23

NOTE: For genetic tests, the ability of genotype to predict phenotype associated with the clinical condition.


clinical validity

the accuracy with which a test predicts the presence or absence of a clinical condition or predisposition;

Project: I/LA28

NOTE: With immunohistochemistry assays, the clinical validity for the presence or absence of a biomarker in tissues to confirm the histogenesis (lineage) of a tumor, prognosis of a tumor, or prediction of the effectiveness of a therapeutic agent.


clinically reportable interval

(CRI) the range of measurand values that a method can report as a quantitative result, allowing for specimen dilution, concentration, or other pretreatment used to extend the direct analytical measuring interval.

Project: H26, GP26


clinically reportable range

(CRR) the range of analyte values that a method can report as a quantitative result, allowing for sample dilution, concentration, or other pretreatment used to extend the direct analytical measurement range (AMR) (EP09);

Project: H57

NOTE 1: For example, if it is desired to report a result that exceeds the AMR, the specimen is commonly diluted to bring the analyte into that range, the diluted specimen is reassayed, and the final result calculated using the dilution factor (H57); NOTE 2: The establishment of the CRR is a medical judgment made by the laboratory director, and is based in part on the assay technology (H57).


clinically significant antibody

antibodies that have been associated with hemolytic disease of the fetus and newborn, a hemolytic transfusion reaction, or notably decreased survival of transfused red cells.

Project: ILA33


clinician

provider of clinical services

Project: GP49

NOTE: Clinicians are often physicians but may also be advanced practitioners, such as physician assistants, nurse practitioners, and midwives.


clonal marker

a marker that allows the identification of the progeny from a monoclonal cell proliferation, derived from a single cell (a clone).

Project: MM19


clone

a population of identical units, organisms, cells, or individuals that derive from the same ancestral line.

Project: NRSCL8


clone

to cause to grow as a clone


clone

to separate (a batch of cells or cell products) so that each portion produces only its own kind


clone

(as applied to a monoclonal antibody) the individual hybridoma cell line from which a monoclonal antibody is derived;

Project: I/LA28

NOTE: The hybridoma cells are separated into single cell isolates and clonally expanded from these individual single cells. Antibody is isolated from the clonally expanded populations and screened for function. Each cell in a hybridoma clone is identical, all sharing a single progenitor and, as such, produces an identical antibody.


close call

event or situation that could have resulted in an adverse event, accident, injury, or illness; but did not, either by chance or through timely intervention;

NOTE: Such events have also been referred to as near-miss incidents


closed system

a system in which the vendor provides all hardware and software to the health care organization. The majority of medical devices are closed systems.

Project: AUTO11


closed system

reactions that occur in a single reaction vessel and require no separate postamplification analysis to generate a result.

Project: MM19


closed-container sampling

the action of aspirating a sample from a container/tube with the closure in place, requiring the sample probe to pierce the closure of the container/sample container.

Project: AUTO01, AUTO02


closed-tube sampling

See closed-container sampling.

Project: AUTO02


closure coating

lubricant or other material applied to the container closure.

Project: GP39


clot activator

material used to initiate the clotting mechanism

Project: GP39, GP34


clot reaction curve

graphical (visual) representation of the clotting reaction measuring the optical output data recorded during clotting tests (eg, prothrombin time, activated partial thromboplastin time, factor assays)

Project: H48


cloud

a software model in which data, resources, and the software are shared and provided to clients over the Internet, based on demand.

Project: AUTO11


CLSI

Clinical and Laboratory Satandards Institute (formerly NCCLS [until 1 January 2005]: National Committee for Clinical Laboratory Standards)


CLSI standard

a document developed through the consensus process that clearly identifies specific, essential requirements for materials, methods, or practices for use in an unmodified form (EP07);

Project: EP07

NOTE: A standard may, in addition, contain discretionary elements, which are clearly identified (EP07).


cluster of differentiation system

(CD system) the identification of monoclonal antibodies with similar patterns of reactivity with human cells, which was the focus of numerous international workshops;

Project: H43, H42, H52

NOTE: Each group of antibodies was assigned a CD number. Not all antibodies in a CD group react with identical portions (epitopes) of their target antigen. An antigen recognized by a given cluster of antibodies (eg, CD4) is referred to as a "CD antigen" (eg, CD4 antigen). An antibody that belongs to a given cluster is referred to as CD "x," with the manufacturer’s nomenclature given in parentheses (eg, CD4 [Leu3a]) (H42).


cluster sequencing

sequencing of a DNA template prepared by clonal amplification on a solid support in a cell-free system.

Project: MM09


coagulation

the process by which the coagulation factors in blood interact to form a clot (Cf. POL1/2).

Project: POL1/2


coagulation factor

one of a group of components of blood plasma that interact to form a blood clot

Project: H48, H47


coagulation factors

the various components of the blood coagulation system (H21);

Project: H21

NOTE: The following factors (including synonyms which are, or were in use) are known:
Factor I (fibrinogen)
Factor II (prothrombin)
Factor III (commonly termed thromboplastin, tissue factor)
Factor IV (commonly termed calcium)
Factor V (labile factor)
Factor VII (stable factor)
Factor VIII (antihemophilic factor [AHF], antihemophilic globulin [AHG], antihemophilic factor A, Factor VIII:C)
Factor IX (plasma thromboplastin component [PTC], Christmas factor, antihemophilic factor B)
Factor X (Stuart factor, Prower factor, Stuart-Prower factor)
Factor XI (plasma thromboplastin antecedent [PTA], antihemophilic factor C)
Factor XII (Hageman factor, surface factor, contact factor)
Factor XIII (fibrin stabilizing factor [FSF], fibrin stabilizing enzyme, fibrinase)
Other factors: (prekallikrein [Fletcher factor], high molecular weight kininogen [Fitzgerald factor]) (H21).


coagulation meter

device to assess the clotting time.

Project: POCT07


coagulation test system

a device used to measure the rate of clotting of blood or plasma

Project: POCT14


coagulometer

an analytical instrument for measuring coagulation parameters (H57).

Project: H57


cocktail

a mixture of two or more monoclonal antibodies or fluorescent reagents.

Project: H52


cocktail immunoassay testing

a practice in which multiple specimens are combined and tested as one, or multiple antibodies to different drug classes are combined in an effort to reduce the total number of analytical tests

Project: C52

NOTE 1: If any cocktailed specimens are positive then the original specimens are retested to determine which particular specimen(s) is positive; NOTE 2: If any cocktailed reagent produces a positive result for a particular specimen, then the original specimen(s) is retested with an individual reagent(s) to determine which specific drug is present.


cocktailing

process of combining two or more monoclonal antibodies or fluorescent reagents.

Project: H52


COCL

the value selected by inspecting clinical/microbiological outcome vs MIC from prospective clinical studies will be called the “clinical” cutoff” and will be abbreviated COCL. This estimate is to be used in the establishment of interpretive criteria by the subcommittee, as described in Appendix C. It is not intended to be reported to clinical laboratories and will not be published within CLSI documents.

Project: VET02


Code of Federal Regulations

(CFR) Published by the Office of the Federal Register, National Archives and Records Administration as a special edition of the Federal Register


codes

a collection of laws in writing

Project: QMS04


coding

a process that adjusts the glucose meter to use the proper calibration.

Project: POCT13


coefficient

in the context of quantitative clinical laboratory measurement procedures, the calculated values for B (subscript 0 through 4) for the multiple linear regression equation (EP10).

Project: EP10


coefficient of determination

the square of the correlation coefficient.

Project: NRSCL08


coefficient of variation

standard deviation divided by the mean (ISO 3534-1)

Project: EP33, QMS24, EP10, C24, C54, H57, H26, MM06, C51

NOTE 1: The ratio may be expressed as a percentage; NOTE 2: The term "relative standard deviation" is sometimes used as an alternative to "coeffficient of variation" but this use is not recommended; NOTE 3: It is often multiplied by 100 and expressed as a percentage; NOTE 4: It is a measure of relative imprecision; it is often multiplied by 100 and expressed as a percentage and abbreviated as %CV (EP10); NOTE 5: It is calculated as 100 times the standard deviation (SD), divided by the mean, and expressed as a percentage (%CV) (H26); NOTE 6: The coefficient of variation is commonly reported as a percentage; NOTE 7: The predecessor term "relative SD" is deprecated by the term CV.


coefficient of variation

(CV) a measure of relative precision

Project: ISO 3534

NOTE 1: For a non-negative characteristic, the ratio of the standard deviation to the average; NOTE 2: It is often multiplied by 100 and expressed as a percentage.


coenocytic

aseptate with no cross-walls separating the cells.

Project: M54


coenzyme

a small nonprotein substance required in an enzyme reaction;

Project: NRSCL8

NOTE: Some coenzymes are also substrates (Cf. DI1).


cofactor

a nonsubstrate coenzyme (Cf. DI1)

Project: DI01


cognitive error

error of incorrect choices, owing to insufficient knowledge, misinterpretation of available information, or application of the wrong cognitive rule (ISO/TS 22367)

Project: ISO/PDTR 22367


cognitive error

error made from mistakes in decision-making and problem-solving;

NOTE: Mistakes typically involve insufficient knowledge, failure to correctly interpret available information, or application of the wrong cognitive rule


coherent derived unit

derived unit that, for a given system of quantities and for a chosen set of base units, is a product of powers of base units with no other proportionality factor than one (JCGM 200:2012)

Project: ISO IEC Guide 99

NOTE 1: A power of a base unit is the base unit raised to an exponent (JCGM 200:2012); NOTE 2: Coherence can be determined only with respect to a particular system of quantities and a given set of base units. EXAMPLES: If the metre, the second, and the mole are base units, the metre per second is the coherent derived unit of velocity when velocity is defined by the quantity equation v = dr/dt, and the mole per cubic metre is the coherent derived unit of amount-of-substance concentration when amount-of-substance concentration is defined by the quantity equation c = n/V. The kilometre per hour and the knot, given as examples of derived units in 1.11, are not coherent derived units in such a system of quantities (JCGM 200:2012); NOTE 3: A derived unit can be coherent with respect to one system of quantities but not to another. EXAMPLE: The centimetre per second is the coherent derived unit of speed in a CGS system of units but is not a coherent derived unit in the SI (JCGM 200:2012); NOTE 4: The coherent derived unit for every derived quantity of dimension one in a given system of units is the number one, symbol 1. The name and symbol of the measurement unit one are generally not indicated (JCGM 200:2012).


coherent system of units

system of units, based on a given system of quantities, in which the measurement unit for each derived quantity is a coherent derived unit (JCGM 200:2012)

Project: ISO IEC Guide 99

EXAMPLE: Set of coherent SI units and relations between them (JCGM 200:2012); NOTE 1: A system of units can be coherent only with respect to a system of quantities and the adopted base units (JCGM 200:2012); NOTE 2: For a coherent system of units, numerical value equations have the same form, including numerical factors, as the corresponding quantity equations (JCGM 200:2012).


cohort study

type of observational study design in which determination of exposure precedes determination of outcome

Project: GP45

NOTE 1: In this study design, subsets of a defined population are identified who are, have been, or in the future may be exposed or not exposed, or exposed in different degrees, to a factor or factors hypothesized to influence the possibility of occurrence of a given disease or other outcome of interest; NOTE 2: The main feature of cohort study is observation of large numbers over a long period (commonly years) with comparison of incidence rates in groups that differ in exposure levels. An essential feature of the method is observation of the population for a sufficient number of person-years to generate reliable incidence or mortality rates in the population subsets. This generally implies study of a large population, study for a prolonged period (years), or both. The denominator may be persons or person-time; NOTE 3: Cohort studies may be conducted prospectively, as described above, or "retrospectively" as historical cohort studies. Such studies use existing records about the health or other relevant aspects of a population as it was at some time in the past and determines the current (or subsequent) status of members of this population with respect to the condition of interest.


coin lesion

a well-circumscribed, calcified lung lesion resembling the shadow of a coin on an X-ray.

Project: M54


cold temperature

a temperature maintained thermostatically between 2 and 8°C (36 to 46°F).

Project: M40


collection vessel

any tube or container, preferably plastic, which serves to contain the body fluid specimen.

Project: H56


collision-induced dissociation

(CID) a process wherein a (fast) projectile ion is dissociated as a result of interaction with a target neutral species;

Project: C50

NOTE: This is brought about by conversion, during the collision, of part of the ion’s translational energy to internal energy.


collision-induced dissociation

(CID) dissociation of an ion after collisional excitation (IUPAC 2006).

Project: C43


colloid

small, solid particles that will not settle out of a solution

Project: GP40


color compensation

in flow cytometry, electronic or mathematical subtraction of a fraction of one signal from a second;

Project: NRSCL8

NOTE: Used in correcting for overlapping fluorescence from one fluorochrome in the wavelength region where the second is to be measured so that populations stained exclusively with each fluorochrome appear at right angles to each other.


color compensation

a mathematical or electronic correction applied to flow cytometric data to account for the overlapping fluorescence emission from one fluorochrome in the wavelength region where the second is measured (H42, H43);

Project: H43, H42

NOTE: Compensation is achieved by subtracting a fraction of one measured fluorescence signal from each of the other fluorescent signals, the amount for subtraction determined from appropriate single-stained controls. The number of signals involved is equal to the number of fluorochromes (N) used and the number of compensation coefficients to be determined represented by an N x N dimensional matrix. The result is that each corrected signal reflects the emission of a single fluorochrome (H42, H43).


color compensation

mathematical (software) or electronic correction applied to flow cytometric data to account for the overlapping fluorescence emission from one fluorochrome in the wavelength region where the second is measured;

Project: H52

NOTE: Compensation is achieved by subtracting a fraction of one measured fluorescence signal from each of the other fluorescent signals, the amount for subtraction determined from appropriate single-stained controls. The number of signals involved is equal to the number of fluorochromes (N) used and the number of compensation coefficients to be determined, represented by an N × N dimensional matrix. The result is that each corrected signal reflects the emission of a single fluorochrome.


colorimeter

an instrument used for color measurement based on optical comparison with standard colors (ASTM8).

Project: ASTM08, VET04, VET03


colorimetry

the measurement and analysis of color by comparison with a standard (Cf. POL1/2).

Project: POL1/2


colposcopy

a procedure where a dissecting-type microscope is used to view the cervix following an application of dilute acetic acid, which colors the cervical intraepithelial neoplasia (CIN) lesions transiently white (acetowhite) and/or accentuates abnormal vasculature to facilitate the identification of intraepithelial lesions and cancer for biopsy;

Project: GP15

NOTE 1: Colposcopy is done following an abnormal Pap test result, or in the investigation of symptoms of cervical pathology such as abnormal vaginal bleeding, even if the Pap test is reported as normal. Colposcopy allows illuminated examination of the lower genital tract to detect epithelial abnormalities and assess severity of these lesions; NOTE 2: Colposcopy is also done when the cervix is visually abnormal in appearance, and when a high-risk (HR) HPV test is positive in the following clinical situations: 1) postcolposcopy follow-up of women treated for CIN 2,3; 2) postcolposcopy follow-up of women not found to have CIN 2,3 or adenocarcinoma in situ (AIS) at initial colposcopy and referred for the evaluation of repeat atypical squamous cells of undetermined significance (ASC-US), atypical squamous cells—cannot exclude high-grade squamous intraepithelial lesion (ASC-H), low-grade squamous intraepithelial lesion (LSIL), and atypical glandular cells not otherwise specified (AGC-NOS); and 3) follow-up of women age 30 and over having a normal Pap and a positive HR HPV test on the initial screen, and either a positive HR HPV test and/or an abnormal Pap on the 12-month follow-up exam.


combination immunoassay

an immunoassay that detects both antigen and antibody.

Project: M53


combined standard measurement uncertainty

See combined standard uncertainty.

Project: C51


combined standard uncertainty

(measurement) standard measurement uncertainty that is obtained using the individual standard measurement uncertainties associated with the input quantities in a measurement model (JCGM 200:2012)

Project: ISO IEC Guide 99, C53, EP29

NOTE 1: In case of correlations of input quantities in a measurement model, covariances must also be taken into account when calculating the combined standard measurement uncertainty (JCGM 200:2012); see also ISO/IEC Guide 98-3:2008, 2.3.4; NOTE 2: The symbol for a combined standard uncertainty is uc (JCGM 100:2008).


combustible liquid

a liquid with a flash point of 38°C (100°F) or higher, but generally below  93.3°C (200°F)

Project: QMS04


commercial in vitro diagnostic device

an in vitro diagnostic (IVD) kit or reagent that has been validated by a commercial manufacturer to produce clinically meaningful results under very specific preexamination and examination conditions;

Project: MM07

NOTE: Deviation from those conditions may affect the results obtained with the IVD device.


committee

group chosen to do a task;

Project: QMS14

NOTE: A group of people appointed or chosen to perform a function on behalf of a larger group.


committee charter

rights delegated to a committee including scope of activity and terms of reference.

Project: QMS14


Common Access Point

(CAP) an Access Point that can service MIB, POC, and hand-held PDA devices.

Project: POCT01


common blood coagulation pathway

the activation of Factor X by Tissue Factor/VIIa complex and/or Factor IXa, followed by activation of Factor II and conversion of fibrinogen to fibrin

Project: POCT14


common carrier

company or utility publicly and indiscriminately engaging in the regular business of transporting people or freight, under license or authority of a regulatory body;

Project: GP36

NOTE: A common carrier is distinguished from a contract carrier, which serves specific clients.


common cause variation

variation resulting from sources inherent in the testing process (GP29);

NOTE: Also known as "random variation" or "process variation" (GP29).


common determinant

a cluster of epitopes that identify related antigens;

Project: NRSCL8

NOTE: The C1 portion of light chains from immunoglobulins IgG, IgA, IgM, IgD, and IgE; or the portion of IgH chains that is identical in humans, monkeys, goats, and rabbits (Cf. DI1).


communication

exchange and flow of information and ideas;

Project: QMS16

NOTE: Communication is a process by which information is exchanged between individuals through a common language or system of symbols, signs, or behavior.


commutability

(of a material) closeness of agreement between the mathematical relationship of the measurement results obtained by two measurement procedures for a stated quantity in a given material, and the mathematical relationship obtained for the quantity in routine samples (ISO 17511, ISO 18153)

Project: ISO 17511, ISO 18153, X5

NOTE: For reference materials used to calibrate measurement procedures intended for use by medical laboratories, the routine samples shall include samples from healthy and relevantly diseased individuals.


commutability

(of a reference material) property of a reference material, demonstrated by the closeness of agreement between the relation among the measurement results for a stated quantity in this material, obtained according to two given measurement procedures, and the relation obtained among the measurement results for other specified materials (JCGM 200:2012)

Project: EP21, QMS24, ISO IEC Guide 99, C53, MM06, EP23, EP29, EP26, C62

NOTE 1: The reference material in question is usually a reference material (calibrator) and the other specified materials are usually routine samples (modified from JCGM 200:2012); NOTE 2: The measurement procedures referred to in the definition are the one preceding and the one following the reference material (calibrator) in question in a calibration hierarchy (see ISO 17511) (JCGM 200:2012); NOTE 3: The stability of commutable reference materials is monitored regularly (JCGM 200:2012); NOTE 4: Commutability is a property of a reference material, demonstrated by the equivalence of the mathematical relationships among the results of different measurement procedures for a reference material and for representative samples of the type intended to be measured; NOTE 5: The equivalence of the mathematical relationships among the results of different measurement procedures for a reference material and for representative samples from healthy and diseased individuals (modified from ISO 17511); NOTE 6: In the context of EP26, two different reagent lots are considered to behave as two different “measurement procedures,” because that phrase is used in the preceding definition of commutability; NOTE 7: The term “commutable material” is used in QMS24 to describe a proficiency testing material that responds to measurement methods in the same manner as patient specimens.


commutability

the equivalence of the mathematical relationships among the results of different measurement procedures for a reference material and for representative samples of the type intended to be measured

Project: EP10

NOTE: This is equivalent to the ISO definition, ie, closeness of the agreement between the mathematical relationship of the measurement results obtained by two measurement procedures for a stated quantity in a given material, and the mathematical relationship obtained for the quantity in routine samples (ISO 17511).


commutability

(of a material) ability of a material to yield the same numerical relationships between results of measurements by a given set of measurement procedures, purporting to measure the same quantity, as those between the expectations of the relationships obtained when the same procedures are applied to other relevant types of material (ISO 15198)

Project: ISO 15194, ISO 15198, ISO 15197, ISO DIS 17593, ISO DIS 18113-1

NOTE 1: This means that two different measurement procedures calibrated with the same material will yield equivalent results for representative samples of the type intended to be measured (ISO/DIS 18113-1); NOTE 2: The material in question is usually a calibrator (ISO/DIS 18113-1); NOTE 3: At least one of the two given measurement procedures is usually a high-level measurement procedure (ISO 15197, ISO/DIS 17593).


commutability

(of a reference material) a property of a reference material, demonstrated by the equivalence of the mathematical relationships among the results of different measurement procedures for a reference material and for representative samples of the type intended to be measured (C53).

Project: C53


commutability

(of a reference material) property of a given reference material, demonstrated by the closeness of agreement between the relationamong the measurement results for a stated quantity in this material, obtained according to two measurement procedures, and the relation obtained among the measurement results for other specified materials (ISO 15194)

Project: ISO 15194, EP14

NOTE 1: The reference material in question is usually a calibrator and the other specified materials are usually routine samples (ISO 15194); NOTE 2: The measurement procedures referred to in the definition are the one preceding and the one following the reference material (calibrator) in question in a calibration hierarchy (ISO 15194).


commutable

interassay properties of a reference material, calibrator material, or quality control material that are comparable with those demonstrated by authentic clinical specimens;

Project: prEN 12287, C37, C54

NOTE: Commutability of a material is defined as the "degree to which a material yields the same numerical relationships between results of measurements by a given set of measurement procedures, purporting to measure the same quantity, as those between the expectations of the relationships obtained when the same procedures are applied to other relevant types of material" (CEN prEN 12287:1999, 3.5).


companion diagnostic device

an in vitro diagnostic (IVD) device or an imaging tool that provides information that is essential for the safe and effective use of a corresponding therapeutic product;

Project: MM23

NOTE: The use of an IVD companion diagnostic device with a particular therapeutic product is stipulated in the instructions for use in the labeling of both the diagnostic device and the corresponding therapeutic product, as well as in the labeling of any generic equivalents and biosimilar equivalents of the therapeutic product; EXAMPLE: A BRAF testing kit is an IVD device intended for the qualitative detection of the BRAF V600E and V600K mutations in DNA samples extracted from formalin-fixed, paraffin-embedded human melanoma tissue. It is intended to be used as an aid to select melanoma patients with tumors that have this mutation and are most likely to respond favorably to specific immunotherapy agents.


comparability

closeness of the agreement between the results of the coagulometer/reagent system under evaluation with an established method (H57).

Project: H57


comparability

agreement between patient results obtained for an analyte (measurand) using different measurement procedures within a health care system (C54);

Project: C54, H26

NOTE: The results are considered to be comparable if the differences do not exceed a critical value established based on defined acceptance criteria (C54).


comparative FTH measurement procedures

rely on use as calibrants of serum containing various total hormone concentrations, in which the corresponding FTH concentration is established by an absolute measurement procedure

Project: C45


comparative measurement procedure

a well-characterized measurement procedure that serves as the basis for assigning the true concentration of an analyte in a sample in an evaluation of a measurement procedure.

Project: EP07


comparative measurement procedure

the measurement procedure used as the basis for comparing two different measurements (eg, in the evaluation of total analytical error) that ideally is traceable to a reference measurement procedure

Project: EP21


comparative measurement procedure

a measurement procedure whose performance characteristics are considered suitable for clinical use and to which a candidate procedure can be compared to evaluate the latter’s suitability for clinical use.

Project: EP27


comparative method

in a method evaluation experiment, a well-characterized method that serves as the basis for assigning the true concentration of an analyte in a sample.

Project: EP07

NOTE 1: The method(s) being used to validate the new automated system, also known as a comparator method; NOTE 2: The comparative method(s) may be a reference standard or a nonreference standard.


comparative method

the measurement procedure used as the basis for comparing two different measurement procedures (eg, in the evaluation of matrix effects);

NOTE: The more specific this procedure is, the better the conclusion with regard to the source of the observed interference.


comparative method

the method used as the basis for comparing two methods, eg, in the evaluation of matrix effects;

NOTE: The more specific this method is, the better the conclusion with regard to the source of the observed interference.


comparative tube

blood collection tube currently used by the clinical laboratory.

Project: GP34


comparator method

method against which a new system is evaluated;

Project: M52

NOTE: Comparator methods may include reference methods or a previously verified US Food and Drug Administration--cleared commercial system.


comparison of methods

a statistical procedure that is based on data gathered from the paired analysis of the same samples by two different measurement procedures;

Project: EP10

NOTE: Ideally, one of the procedures is a well-accepted or reference measurement procedure, sometimes called a "gold standard."


compatibility testing

for the purposes of this document, meaning is limited to the serological crossmatch; procedure that involves combining of recipient serum or plasma with donor RBC to demonstrate ABO and/or other clinically significant antibody incompatibility.

Project: ILA33


competence

the ability of an individual to perform a specific job or task.


competence

ability to apply knowledge and skills to achieve intended results (ISO 9000)

Project: GP48


competence

application of knowledge, skills, and behaviors in performance (ISO 10015)


competence

ability to apply knowledge and skills to achieve intended results (ISO 9000)

Project: QMS03, ISO 9000, ISO 9001, QMS13, HS02, POCT10, QMS15, QMS20, GP23


competence assessment

evaluation of a person’s ability to apply his or her skill, knowledge, and experience to perform assigned laboratory duties correctly

Project: QMS16, POCT04, QMS03

NOTE: This includes all aspects of testing, from specimen collection to result reporting, and it is usually done with specimens containing known amounts of the analyte(s) for which the specimens are being tested.


competencies

the capability to apply or use a set of related knowledge, skills, and abilities required to successfully perform “critical work functions” or tasks in a defined work setting

Project: QMS16


competency

the circumstance to have demonstrated and documented the ability to correctly perform testing using a point-of-care blood glucose meter system.

Project: POCT12


competency

following successful completion of a training program, the assessment of a person's ability to perform blood glucose testing

Project: POCT17, POCT13


competency assessment

evaluation of a person’s ability to perform a test including all aspects of testing, from specimen collection to result reporting

Project: POCT14


competency testing

evaluating a person's ability to perform a test and to use a testing device;

Project: POCT08

NOTE: This includes all aspects of testing, from specimen collection to result reporting, and it is usually done with specimens or samples containing known amounts of the analytes for which the specimens or samples are being tested.


competitive assay

an assay based on the competition of labeled and unlabeled analytes for a receptor. (Cf. DI1).

Project: DI01, I/LA23


complaint

any concern about the laboratory’s operation;

Project: QMS21, GP26

EXAMPLES: quality of testing, unlabeled specimens, unethical practices, confidentiality of patient information, laboratory qualification, and responsibility issues.


complement

a group of plasma proteins, some of which are enzymes, that are sequentially activated by antigen-antibody complexes or microbial products.

Project: DI01


complement fixation

an immunoassay that uses the complement-mediated lysis of cells to detect the occurrence of an antigen-antibody reaction (Cf. DI1).

Project: DI01


complementary

describing the property of two strands of nucleic acid that can hybridize by specific-base pairing between the nucleotides.

Project: MM01, MM10, MM09, MM12, MM22


completeness

the property that all necessary parts of the entity are included;

Project: AUTO08

NOTE: Completeness of a product is often used to express the fact that all requirements have been met by the product (NBS Special Publication 500-75).


compliance

the act or process of complying to a desire, demand, proposal, or regimen, or to coercion(Merriam Webster)

Project: C52

NOTE: In C52, compliance refers to 1) patient adherence to a clinician’s prescription for a drug regimen, and 2) patient adherence to his or her pain management “contract” that he or she signs with the clinician.


compliance

successful fulfillment of a requirement

Project: QMS17


component

part of a finished, packaged, and labelled IVD medical device (ISO 18113-1)

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3, POCT07

NOTE 1: Typical kit components include antibody solutions, buffer solutions, calibrators, and/or control materials (ISO 18113-1); NOTE 2: Adapted from US Code of Federal Regulations (CFR), Title 21, Part 820 — Quality System Regulation (ISO 18113-1); EXAMPLE: Raw material, substance, piece, part, software, firmware, labeling, or assembly (ISO 18113-1).


component field

a single data element or data elements which express a finer aggregate or extension of data elements which precede it; for example, parts of a field or repeat field entry;

Project: LIS02

NOTE 1: As an example, the patient’s name is recorded as last name, first name, and middle initial, each of which is separated by a component delimiter; NOTE 2: Components cannot contain repeat fields.


compound heterozygote

the presence of two different mutant alleles at a particular gene locus, one on each chromosome of a pair;

Project: MM01

NOTE: A mutation affecting only one allele is called heterozygous. A homozygous mutation is the presence of the identical mutation on both alleles of a specific gene. However, when both alleles of a gene harbor mutations, but the mutations are different, these mutations are called compound heterozygous. This is important, for example, in recessive diseases in which each allele carries a different mutation, one from each parent.


comprehensive CLIA QC

the process of testing every substrate and/or reagent that is part of an MIS for positive and negative reactivity, using biologic QC organisms, with each batch, lot number, and shipment of MIS.

Project: M50


compression

artifacts that are produced during electrophoresis due to the formation of stable secondary structures in the sequencing product DNA fragments;

Project: MM09

NOTE 1: The folded structures run faster through the matrix than equivalent unfolded DNA fragments resulting in odd spacing, or bands very close together followed by bands spaced further apart than normal; NOTE 2: In some cases, bases can be lost entirely.


computer system security

the protection of computer hardware and software from accidental or malicious access, use, modification, destruction, or disclosure;

Project: AUTO08

NOTE: Security also pertains to personnel, data, communications, and the physical protection of computer installations (IEEE 610.12-1990).


concentrate

the liquid containing dissolved and suspended matter that concentrates on one side of a membrane

Project: GP40


concentration

(for antimicrobial agent properties) amount of an antimicrobial agent in a defined volume of liquid (ISO 20776-1)

Project: ISO 20776-1

NOTE 1: The concentration is expressed as mg/L (ISO 20776-1); NOTE 2: mg/L = µg/mL, but it is not recommended to use the unit µg/mL (ISO 20776-1).


concentration

a measure of the amount of dissolved substance per unit of volume (RHUD1.7CD).

Project: VET03


concentration of total hemoglobin

the concentrational (mass concentration, substance concentration) amounts of the total of all forms of hemoglobin present in the sample (Cf. H15, C25).


concentration techniques

procedures, usually in fecal examinations, allowing the examination of large amounts of feces (flotation or sedimentation procedures; some available for blood specimens and urine specimens).

Project: M28


condenser

the stage of a distillation system that removes sufficient heat from a vaporized liquid to cause the vapor to change to a liquid phase

Project: GP40


condition of interest

a particular disease, a disease stage, health status, or any other identifiable condition or characteristic of interest within a subject, such as staging a disease already known to be present, or a health condition that could prompt clinical action, such as the initiation, modification, or termination of treatment (EP12).

Project: EP12


condition of interest

a particular disease, disease stage, health status, or any other identifiable condition within a patient, such as staging a disease already known to be present, or a health condition that should prompt clinical action, such as the initiation, modification, or termination of treatment (defined in STARD [Standards for Reporting of Diagnostic Accuracy] Initiative).

Project: MM17


conditional safety

safety aspects of medical devices dependent on proper use, handling, testing, or installation of the devices, provided by the manufacturer alone or in combination with service providers, such as contract sterilizers and practitioners (ISO Guide 63-2.2).

Project: ISO Guide 63-2.2


conduction

the flow of heat by conduction occurs via collisions between atoms and molecules in the substance and the subsequent transfer of kinetic energy;

Project: GP28

NOTE: When there exists a temperature gradient within a body, heat energy will flow from the region of high temperature to the region of low temperature.


conductivity

conductivity is the reciprocal of resistivity

Project: GP40

NOTE: For water purification systems, conductivity is usually reported in microsiemens per centimeter (µS/cm).


confidence interval

an interval estimate of a population parameter computed so that the statement “the population parameter lies in this interval” will be true... in a stated proportion of the times such statements are made (ASTM8).

Project: ASTM08


confidence interval

the computed interval with a given probability (eg, 95%) that the true value of a variable such as a mean, proportion, or rate is contained within the interval

Project: GP45, ILA21, H57, MM17


confidence level

the value (1 - α) of the probability associated with a confidence interval;

Project: EP07

NOTE: The probability is usually denoted as a percentage: 100 (1 - α) %.


confidence limit

a number or pair of numbers that define a confidence interval;

Project: NRSCL08

NOTE: See also ISO 3534-1-2.60.


confirmation test

a procedure that is based on a different, more specific, physicochemical method than the original screening assay, and used to confirm positive screening test results; confirmation tests are typically quantitative.

Project: C52

NOTE: A confirmatory test determines whether a specimen is ultimately reported as positive or negative. Gas chromatography/mass spectrometry (GC/MS) is generally used for forensic confirmatory testing.


confirmatory assay

a modification of the IgE antibody assay in which drug or buffer (sham control) is first mixed with the test serum and the mixture is analyzed in the assay. Competitive inhibition of the IgE antibody binding to the immobilized or labeled drug by solution phase drug confirms the specificity of the antibody for the drug. Due to the typically low levels of IgE antibody in human serum, competitive inhibition may not be technically possible to achieve.

Project: ILA34


confirmatory test

test to prove or disprove the presence of a specific condition identified by screening tests (for dried blood spot screening, this testing is from a specimen other than the screening specimen)

Project: NBS05


confirmatory test

test to prove or disprove the presence of a specific condition suggested by screening tests

Project: NBS02

NOTE: For dried blood spot screening, this testing is from a specimen other than the original screening specimen.


confirmatory test

a test to prove or disprove the presence of a specific condition suspected because of screening test results (for screening using dried blood spots, this testing is from a specimen other than the screening specimen)

Project: NBS03


confirmatory testing

a test that establishes the presence or absence of a measurand by another method that is either more sensitive, more specific, or both;

Project: MM09

NOTE: A test to confirm the presence or absence of a clinical condition as a follow-up to testing previously performed that indicated the patient being at a higher risk for having a clinical condition.


conflict of interest

situation that has the potential to undermine the impartiality of a person because of the possibility of differences between the person’s self-interest and professional interest or public interest (Business Dictionary)

Project: QMS05


conformance

fulfillment of a requirement (ISO 9000)

Project: QMS02


confounding

1) a situation in which the effects of two processes are not separated; 2) a situation in which the intervention effect is biased because of some difference between the comparison groups apart from the planned interventions, such as baseline characteristics, prognostic factors, or concomitant interventions

Project: GP45

NOTE 1: The distortion of the apparent effect of an exposure on risk brought about by the association with other factors that can influence the outcome; NOTE 2: For a factor to be a confounder, it must differ between the comparison groups and predict the outcome of interest.


conidium

(pl. conidia) an asexual reproductive structure that forms on the side or the end of a hypha or conidiophore.

Project: M54


conjugate

a material produced by attaching two or more substances together;

NOTE: For example, a compound formed by a label coupled with an antibody or antigen.


conjugate

a covalent or noncovalent combination of a large molecule and another molecule;

Project: AST02

NOTE 1: For example, a compound formed by a label coupled with an antibody or antigen (Cf. AST2); NOTE 2: Conjugates of antibody with fluorochromes, radioactive isotopes, or enzymes are often used in immunoassays (Cf. DI1).


conjugate

an assay reagent that is produced by covalently attaching two (or more) substances to each other such as an antibody with a second biolabel (enzyme [horseradish peroxidase, alkaline phosphatase] or biotin), radiolabel, colloidal gold particle, or fluorophor

Project: I/LA20, ILA34

NOTE: In the solid-phase, two-site immunometric assays that have been used historically in diagnostic allergy laboratories, the conjugate is commonly a labeled antihuman IgE reagent. In some recent fluid-phase assays, the conjugate may be a biolabeled allergen reagent.


Connectivity

the ability to reliably transfer test information between a point-of-care testing device and an information system.

Project: POCT01


connectivity

the ability to reliably transfer data between a point-of-care testing device and a computer system database (POCT02).

Project: POCT02


Connectivity Industry Consortium

(CIC) a group of more than 50 healthcare institutions, point-of-care diagnostic vendors, diagnostic test system vendors, and system integrators who formed a consortium in 2000 to address standards for point-of-care connectivity;

Project: POCT01

NOTE 1: The CIC developed a standardization specification within its planned one-year lifetime, and then handed this specification over to CLSI (www.clsi.org), Health Level 7 (www.hl7.org), and IEEE (www.ieee.org) organizations for subsequent maintenance and extension; NOTE 2: The CIC specification forms the basis for the CLSI POCT1 standard.


consensus

in CLSI documents, the substantial agreement by materially affected, competent, and interested parties that is obtained by following the procedures specified for CLSI consensus approval;

Project: NRSCL08, VET03

NOTE: CLSI consensus does not always connote unanimous agreement, but it does mean that the participants in the development of a standard or guideline have considered and resolved all relevant comments and are willing to abide by the resulting agreement.


consensus sequence

the final sequence generated from a compilation of overlapping sequence ladders following the completion of base calling at all positions;

Project: MM18

NOTE: The consensus sequence is believed to be representative of the source nucleic acid.


consensus sequence

the final sequence generated from a compilation of overlapping sequences following the completion of base calling at all positions;

Project: MM09

NOTE: The consensus sequence is believed to be representative of the source nucleic acid.


consensus value

for a reference material, the value of the quantity obtained by interlaboratory testing, or by agreement between appropriate bodies or experts (ISO Guide 30/92-3.3).


conservation of a measurement standard

set of operations necessary to preserve the metrological properties of a measurement standard within stated limits (JCGM 200:2012)

Project: ISO IEC Guide 99

NOTE: Conservation commonly includes periodic verification of predefined metrological properties or calibration, storage under suitable conditions, and specified care in use (JCGM 200:2012).


conservation of a measurement standard

set of operations necessary to preserve the metrological properties of a measurement standard within stated limits (JCGM 200:2012)

NOTE: The operations commonly include periodic calibration, storage under suitable conditions, and care in use.


conserved gene

a sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species

Project: MM18

NOTE: A known set of conserved sequences is represented by a consensus sequence.


consistency

the degree of uniformity, standardization, and freedom from contradiction among the documents or parts of a system or component (IEEE 610.12-1990).

Project: AUTO08


constant

a number that expresses a property, quantity, or relation that remains unchanged under specified conditions.

Project: NRSCL08


constant air volume

(CAV) air supply and exhaust system where the airflow always stays the same

Project: QMS04


construction

(CA) sixth and last design phase of a construction project, in which the actual construction is occurring

Project: QMS04

NOTE: The administration refers to the task of the architect in relation to construction


construction documents

(CD) fourth design phase of a construction project, in which drawings and specifications, which tell the contractors exactly what to purchase and how they should be constructed, are prepared

Project: QMS04

NOTE: In QMS04, “CD” refers to both the “construction documents” phase of laboratory design, and the physical documents associated with this phase. When the latter use is intended, the abbreviation may be pluralized as “CDs” if multiple documents are indicated.


consultative services

organized program supported by dedicated staff at a referral laboratory, designed to provide specific information to referring laboratory clients to facilitate the ordering and performance of examinations or the interpretation of examination results

Project: QMS05

NOTE: A consultation may involve technical information or medical interpretive information.


consumable materials

materials that are used and then disposed, become incorporated into other materials and lose their identity, or cannot be used for their intended purpose without obliterating or transforming their substance

Project: QMS21

EXAMPLES: Disposable pipettes, pipette tips, test tubes, instrument cuvettes; reagents and controls; label stock.


contact (transmission)

the spread of infectious agents through the direct transfer of microorganisms from one person to another or indirect transfer of microorganisms from a contaminated object or person.

Project: M29


contact activator

a particulate (eg, kaolin, celite, silica) or soluble (eg, ellagic acid) substance which activates the “contact phase of coagulation,” involving Hageman Factor (Factor XII), Prekallikrein, and HMW Kininogen, thereby initiating the intrinsic phase blood coagulation pathway (ie, activation of Factors XI and IX).

Project: POCT14


contact activator

a substance that activates coagulation Factor XII to active proteolytic enzyme (H47);

Project: H47

NOTE: These activators are normally negatively charged particulate substances but may be soluble compounds (H47).


contact precautions

applied to patients known or suspected to have serious illnesses easily transmitted by direct patient contact or by contact with items in the patient's environment


contact transmission

the spread of infectious agents through the direct transfer of microorganisms from one person to another or indirect transfer of microorganisms from a contaminated object or person.


contactor membrane

a hydrophobic membrane used in removing dissolved gases from water

Project: GP40


container

the receptacle that contains the specimen (H21).

Project: H21


container

See specimen collection container.

Project: AUTO02, AUTO12


container failure

any situation that leads to the loss of the specimen or its alteration so as to render it unsatisfactory for analysis.

Project: M40


container interior


contaminant

a microorganism isolated from a blood culture that was introduced into the culture during specimen collection or processing and that was not pathogenic for the patient from whom blood was collected (i.e., the isolates were not present in the patient's blood when the blood was sampled for culture).

Project: M47


contaminant

a microorganism, chemical, or other material that makes something impure by contact or mixture with it.

Project: M29, POL1/2


contaminated

presence or the reasonably anticipated presence of blood or other potentially infectious materials on an item or surface (20 CFR 1910.1030).

Project: X03, M29


contaminated sharps

any contaminated object that may inflict a puncture or laceration of the skin including, but not limited to, needles, scalpels, broken glass, lancets, and broken capillary tubes.

Project: M29


contaminated sharps

any contaminated object that can penetrate the skin including, but not limited to, needles, scalpels, broken glass, broken capillary tubes, and exposed ends of dental wires.

Project: X03


contig

any contiguous stretch of sequence data created by read overlap.

Project: MM09


contingency plan

a coordinated strategy that involves plans, procedures, and technical measures to enable the recovery of systems and continued operations after a disruption.

Project: HS11


continual improvement

recurring activity to enhance performance (ISO 9000)

Project: QMS19, QMS11, QMS06, EP23, MM20, QMS14, QMS15, QMS20

NOTE 1: Also known as continuous improvement; NOTE 2: Continual improvement includes the actions taken throughout an organization to increase the effectiveness and efficiency of activities and processes in order to provide added benefits to the customer and organization.


continuing education

formal lectures, courses, seminars, webinars, or any other similar type of educational program designed to educate an individual and give him or her further skills or knowledge to be applied in his or her line of work

Project: QMS16, QMS03

NOTE: Training activities for an individual’s current job functions, tasks, and responsibilities are not considered continuing education.


continuous monitoring

for the purposes of ambulatory monitoring, a sensor is considered continuous if it provides a value at least every 15 minutes or more frequently (POCT05).

Project: POCT05


contract review

defined activities carried out before entering into a contract agreement to ensure that requirements are adequately defined and understood, and can be achieved (ISO 8402, 3.10).


contractor

a person who is hired through an agreement or other arrangement to perform a service or to provide goods at a certain price or within a certain period of time

Project: QMS16

NOTE: A consultant is an example of a contractor.


control

(control material) a device, solution, lyophilized preparation, or panel of collected human or animal specimens, or artificially derived materials, intended for use in the quality control process;

Project: EP12, MM10, H47, H44, NRSCL08, MM12, VET03, C34, ILA34

NOTE 1: The expected reaction or concentration of analytes of interest are known within limits ascertained during preparation and confirmed in use; NOTE 2: Control materials should not be used for calibration in the same process in which they are used as controls (EP12); NOTE 3: The control serum should possess a matrix similar in ionic charge, density, pH, and protein content to that of the test specimens. It serves as the primary quality control check on the validity of the calibration-reference curve, the assay reagents, and any required equipment. Moreover, it allows computation of interassay variation using values obtained from more than 10 individual assay runs. A range of values (2 SD, 95% confidence interval) are computed for the control specimen and should be used in Levey-Jennings quality control charts to identify assays that are in or out of control; NOTE 4: The control serum should theoretically possess a matrix similar to that of the test specimen (eg, with similarity in ionic charge, density, pH, and protein content). It serves as the primary quality control check on the validity of the calibration-reference curve, the assay reagents, and any required equipment.


control

to monitor the status of an analysis to maintain its performance within desired limits

Project: MM10, POCT04, MM17


control

(plasma) a batch of citrated plasma used to monitor the stability of the laboratory test system, which includes reagents, instruments, reconstituting and diluting fluids, and pipettes (H30);

Project: H30

NOTE 1: "Normal control plasma" gives test results within the range of the reference interval; NOTE 2: "Abnormal control plasmas" for factor assays should contain factor concentrations below the reference interval values due to abnormally low factor concentrations; NOTE 3: If factors are clinically elevated, the "abnormal control plasma" should contain factor concentrations above the reference interval; NOTE 4: Normal and abnormal control plasmas may be prepared in the laboratory or obtained commercially (H30).


control

an alternate acceptable term for "control material."

Project: EP12


control

administration of an antimicrobial to animals, usually as a herd or flock where clinical symptoms or signs are not present in all individual animals or in which morbidity and/or mortality may exceed baseline norms if not treated, ie, early in the course of the onset of disease in the population;

Project: VET01

NOTE 1: It must be recognized that the initial treatment might be made empirically based on the urgency of the situation, the clinical judgment (including the most likely etiological agent), and experience of the veterinarian. However, a pretreatment culture and subsequent susceptibility information should be obtained as soon as possible to guide the appropriate use of an antimicrobial; NOTE 2: Control does not necessarily consider the health status of a given individual in the population, as that will vary depending upon the disease progression. In other words, a range of clinical manifestations may be present in a group of animals. The objective is to control the dissemination of the disease within the group while treating those with clinical signs. Certain exceptions, such as medication of one-day-old chicks, is discussed in VET01.


control

a device, solution, lyophilized preparation, or cellular element intended for use in the quality control process;

Project: I/LA28

NOTE 1: The expected reaction or concentration of analytes of interest are known within limits ascertained during preparation and confirmed in use; NOTE 2: Control materials are generally not used for calibration in the same process in which they are used as controls; NOTE 3: With regard to immunohistochemistry, controls are usually cells or tissues with known immunoreactivity or normal internal elements within the patient specimen with known immunoreactivity.


control

a standard sample included in an assay to assess the validity of the test. A control has a predicted outcome with an acceptable range of values.

Project: MM06


control

a material, solution, or lyophilized preparation intended for use in the quality control process;

Project: MM01

NOTE 1: The expected reaction or concentration of measurands (analytes) of interest are known within limits ascertained during preparation and confirmed in use; NOTE 2: Control materials are generally not used for calibration in the same process in which they are used as controls.


control

(control material) a device, solution, or lyophilized preparation intended for use in the quality control process

Project: NBS05, MM22

NOTE 1: The expected reaction or concentration of analytes (measurands) of interest are known within limits ascertained during preparation and confirmed in use; NOTE 2: Control materials are generally not used for calibration in the same process in which they are used as controls.


control interval

statistically justified values specified as acceptable measured values obtained using a given control material (ISO 17593)

Project: ISO 17593


control limit

the most extreme value of a quality control material that is still considered to be acceptable.


control material

A device, solution, or lyophilized preparation intended for use in the quality control process to monitor the reliability of a test system and to maintain its performance within established limits

Project: POCT04, POCT14, POCT08, MM03

NOTE 1: The expected reaction or concentration of analytes of interest are known within limits ascertained during preparation and confirmed in use; NOTE 2: Control materials are generally not used for calibration in the same process in which they are used as controls.


control material

substance, material, or article intended by its manufacturer to be used to verify the performance characteristics of an in vitro diagnostic medical device (ISO 15197).

Project: ISO 15197, H26


control material

a device, solution, lyophilized preparation, or panel of collected human or animal specimens, or artificially derived materials, intended for use in the quality control (QC) process

Project: I/LA20

NOTE: The control serum should possess a matrix similar in ionic charge, density, pH, and protein content to that of the test specimens. It serves as the primary QC check on the validity of the calibration-reference curve, the assay reagents, and any required equipment. Moreover, it allows computation of interassay variation using values obtained from more than 10 individual assay runs. A range of values (two standard deviations, 95% confidence interval) are computed for the control specimen and should be used in Levey-Jennings QC charts to identify assays that are in or out of control as a result of observed shifts and trends.


control material

substance, material, or article intended by the manufacturer to be used to verify the performance characteristics of an in vitro diagnostic medical device (ISO 17593)

Project: ISO CD 18112-1, ISO 15197, ISO 17593, ISO 18113-1, ISO 18113-2, ISO 18113-3

NOTE: Control materials for anticoagulation monitoring may be reactive or nonreactive. A reactive control material participates in a reaction with the reagent components. A nonreactive control does not react with the reagent components, but may provide control functionality through other means, eg, a simulation of the reaction (ISO 17593).


control material

substance, material, or article used to verify the performance characteristics of an in vitro diagnostic medical device (ISO 15198)

Project: ISO 15198


control material

See control.

Project: I/LA28


control material

a device, material, solution, or lyophilized preparation intended for use in the quality control process;

Project: H26, MM19, VET04

NOTE 1: It should be similar to, and is analyzed along with, patient specimens. If different, it should have a recognized, defined response to analytical measurements. Control materials may or may not have known measurand concentrations (ie, assigned values) within specified limits (eg, target value, standard deviation). Control materials are not used for calibration purposes; NOTE 2: The expected reaction or concentration of analytes of interest are known within limits ascertained during preparation and confirmed in use; NOTE 3: Control materials are generally not used for calibration in the same process in which they are used as controls.


control material

See control.

Project: MM01


control measure

action taken to reduce risk; action taken to reduce risk;

Project: EP18

NOTE 1: Some examples of the action are a policy, procedure or procedure change, and product or product change; NOTE 2: Also called mitigation; NOTE 3: Similar to a corrective action, but for an event that has not happened.


control number

See batch code and lot number

Project: GP39


control of infection plan

set of procedures to be used to limit spread of infection in either a hospital or a laboratory (ISO 15190)

Project: ISO 15190


control plasma

a preparation of fresh, frozen, or lyophilized plasma collected from human or animal blood, or artificially derived material, intended for use in the quality control process;

Project: H30, H51

NOTE 1: Control plasmas are used to monitor all aspects of the laboratory test system, including the reagents, instruments, reconstituting and diluting fluids, and pipettes; NOTE 2: Normal controls should give test results within the reference interval; NOTE 3: Abnormal control plasmas should give values within the clinically relevant abnormal range.


control point

a point, step, or procedure in a process at which a control can be applied and, as a result, a hazard can be prevented, eliminated, or reduced.

Project: EP23


control procedure

operational techniques and activities at the point of use to monitor the performance of an IVD medical device and fulfill requirements for quality (modified from ISO 15198)

Project: ISO CD 18112-1

NOTE 1: In the IVD medical device industry and in many in vitro diagnostic laboratories, these activities are commonly referred to as quality control (ISO 15198); NOTE 2: The control procedure may monitor all or part of the measurement procedure, from the collection of sample to reporting the result of the measurement (ISO 15198); NOTE 3: In some laboratory quality systems, control procedures within the laboratory have been referred to as"internal quality control."


control procedure

activities at the point of use to monitor the performance of an IVD medical device (ISO 15198)

Project: ISO 15198

NOTE 1: In the IVD medical device industry and in many laboratories that use IVD medical devices, these activities are commonly referred to as quality control (ISO 15198); NOTE 2: Quality control may monitor all or part of the measurement procedure, from the collection of samples to reporting the result of the measurement (ISO 15198).


control procedure

set of operations at the point of use, described specifically, intended to monitor the performance characteristics of an IVD medical device and fulfill requirements for quality (ISO 18113-1)

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3

NOTE: Control procedures can be intended to monitor all or part of the IVD examination process, from the collection of the sample to reporting the result of the examination (ISO 18113-1).


control range

interval of statistically justified acceptable values specified by the manufacturer for results obtained using the control material


control tube

any reference tube used as a comparative tube when evaluating a new or substantially modified tube;

Project: GP34

NOTE: In the United States, these tubes must be US Food and Drug Administration (FDA) cleared.


controlled copy

an approved document that bears all appropriate document control markings such as identification and revision status;

Project: QMS02

NOTE: Controlled copies are distributed for use within the facility and are accounted for when revisions are made, to ensure that obsolete copies are removed from potential use.


controlled room temperature

a temperature maintained thermostatically that encompasses the usual and customary working environment of 20 to 25°C (68 to 77°F) that allows for brief deviations between 15 to 30°C (59 to 86°F) that are experienced in pharmacies, hospitals, and warehouses. For the purposes of this document, controlled room temperature is defined as 20 to 25°C (68 to 77°F), which should be monitored during test performance.

Project: M40


controller

see facilitator.

Project: GP36


convection

the flow of heat through a bulk, macroscopic movement of matter from a hot region to a cool region.

Project: GP28


conventional blood culture system

a blood culture system that processes bottles without the use of mechanical systems (i.e., manually).

Project: M47


conventional quantity value

quantity value attributed by agreement to a quantity for a given purpose (JCGM 200:2012)

Project: ISO IEC Guide 99, EP29, EP15

EXAMPLE 1: Standard acceleration of free fall (formerly called "standard acceleration due to gravity"), gn = 9.806 65 m·s−2 (JCGM 200:2012); EXAMPLE 2: Conventional quantity value of the Josephson constant, KJ-90 = 483 597.9 GHz · V−1 (JCGM 200:2012); EXAMPLE 3: Conventional quantity value of a given mass standard, m = 100.003 47 g (JCGM 200:2012); NOTE 1: The term "conventional true quantity value" is sometimes used for this concept, but its use is discouraged (JCGM 200:2012); NOTE 2: Sometimes a conventional quantity value is an estimate of a true quantity value (JCGM 200:2012); NOTE 3: A conventional quantity value is generally accepted as being associated with a suitably small measurement uncertainty, which might be zero (JCGM 200:2012).


conventional reference scale

quantity-value scale defined by formal agreement (JCGM 200:2012)

Project: ISO IEC Guide 99


conventional smear

a method of slide preparation where a sample of cells collected from the cervix/vagina is smeared and fixed onto a glass slide in the patient examination room.

Project: GP15


conventional true value

(of a quantity) value attributed to a particular quantity and accepted, sometimes by convention, as having an uncertainty appropriate for a given purpose; EXAMPLES a) at a given location, the value assigned to the quantity realized by a reference standard may be taken as a conventional true value; b) the CODATA (1986) recommended value for the Avogadro constant, NA : 6,022 136 7 x 1023 mol-1.

NOTE 1: Conventional true value is sometimes called assigned value, best estimate of the value, conventional value, or reference value. Reference value, in this sense, should not be confused with reference value in the sense used in the NOTE to 5.7 in VIM93; NOTE 2: Frequently, a number of results of measurements of a quantity is used to establish a conventional true value.


conventional true value

a value attributed to a particular quantity and accepted, sometimes by convention, as having an uncertainty appropriate for a given purpose (VIM93-1.20);

NOTE: It is sometimes called assigned value, best estimate of the value, conventional value, or reference value; frequently, a number of results of measurements of a quantity is used to establish a conventional true value (VIM93-1.20).


conventional value

See conventional quantity value.

Project: C51


conventional value of a quantity

See conventional quantity value.

Project: C51


conversion factor between units

ratio of two measurement units for quantities of the same kind (JCGM 200:2012)

Project: ISO IEC Guide 99

EXAMPLE 1: km/m = 1000 and thus 1 km = 1000 m (JCGM 200:2012); NOTE: The measurement units may belong to different systems of units (JCGM 200:2012); EXAMPLE 2: 1 h/s = 3600 and thus 1 h = 3600 s (JCGM 200:2012); EXAMPLE 3: (km/h)/(m/s) = (1/3.6) and thus 1 km/h = (1/3.6) m/s (JCGM 200:2012).


cool temperature

cool temperature – any temperature between 8°C and 15°C (46 to 59°F).

Project: M40


coordinator

person empowered by the manufacturer or investigator with responsibility for the entire performance evaluation (ISO 20776-2)

Project: ISO 20776-2


coordinator

an individual who is responsible for oversight of activities related to a blood glucose monitoring program.

Project: POCT13


CO-oximeter

term commonly used for a multiwavelength photometer for measurement of hemoglobin concentration and relative amounts of oxy-, deoxy-, carboxy-, and methemoglobin components in blood. The process of measuring these species in blood using a multiwavelength photometer is commonly referred to as “CO-oximetry.” An older term, “hemoximetry,” initially referred to the measurement of the oxy- and deoxyhemoglobin species; but it can also include the measurement of carboxy- and methemoglobin, as well.

Project: C46


COPD

the “breakpoint” that can be calculated using PK/PD parameters and Monte Carlo simulation will be called the “pharmacodynamic cutoff” and will be abbreviated COPD. It is established solely on the basis of the relationship between physiologic drug concentrations (eg, blood, or possibly urine or milk) and a microbial susceptibility parameter, generally MIC values. This estimate is to be used in the establishment of interpretive criteria by the subcommittee, as described in Appendix C. It is not intended to be reported to clinical laboratories and will not be published within CLSI documents.

Project: VET02


copolymer

a polymer formed from two or more different monomers

Project: GP40


copy number variant

insertions or deletions that involve a DNA fragment of 1 kb or larger.

Project: MM09


core biopsy

a cylindrical section of tissue that has been removed for pathology analysis, often from a formalin-fixed, paraffin-embedded block.

Project: MM23


corrected result

result of a measurement after correction for systematic error


correction

compensation for an estimated systematic effect (JCGM 200:2012)

Project: ISO IEC Guide 99

NOTE 1: See ISO/IEC Guide 98-3:2008, 3.2.3, for an explanation of ‘systematic effect’; NOTE 2: The compensation can take different forms,such as an addend or a factor, or can be deduced from a table (JCGM 200:2012).


correction factor

numerical factor by which the uncorrected result of a measurement is multiplied to compensate for systematic error (VIM93);

NOTE: Since the systematic error cannot be known perfectly, the compensation cannot be complete.


corrective action

action(s) to eliminate the cause and prevent recurrence of a nonconformity or other undesirable situation

Project: QMS17, QMS19

NOTE: There can be more than one cause for a nonconformity or undesirable situation.


corrective action

action to eliminate the cause of a nonconformity and to prevent recurrence (ISO 9000)

Project: QMS24, ISO 9000, QMS13, QMS11, EP18, POCT09, POCT07, QMS06, GP26, EP23, QMS14, QMS15, QMS20, GP23

NOTE 1: There can be more than one cause for a nonconformity (ISO 9000); NOTE 2: Corrective action is taken to prevent recurrence, whereas preventive action is taken to prevent occurrence (ISO 9000); NOTE 3: Some examples of the action are a policy, procedure or procedure change, and product or product change; NOTE 4: Similar to a corrective action, but for an event that has not happened; NOTE 5: There is a distinction between correction and corrective action; a correction removes a nonconformity, whereas a corrective action removes the cause of the nonconformity (ISO 9000).


correctness

1) the degree to which software is free from faults in its specification, design, and coding; 2) the degree to which software, documentation, and other items meet specified requirements; 3) the degree to which software, documentation, and other items meet user needs and expectations, whether specified or not (IEEE 610.12-1990).

Project: AUTO08


correlation

1) the relationship between two, or several, random variables within a distribution of two or more random variables (ISO 3534-1/93-1.13); 2) the comparison of results between the test (new) measurement procedure and the reference (old) measurement procedure

Project: POCT04, ISO 3534-1, H26

NOTE: High method correlation does not imply high numeric agreement of analytical results but only the predictability of one method’s results by the other method. As Westgard notes, “the fact that the correlation coefficient is commonly calculated doesn’t make it useful,” which simply means that r = 1 alone does not imply that test and comparative methods give the same result.


correlation

the degree to which two variables are proportionally related to each other

Project: POCT14

NOTE: High method correlation does not imply high numeric agreement of analytic results, but only the predictability of one method’s results by the other method.


correlation coefficient

mean of the product of two standardized random variables in their joint probability distribution (ISO 3534-1)

NOTE 1: The value of “r” will always be between -1 and +1; NOTE 2: When r = 1, there exists an exact linear relationship (ISO 3534-1/93-2.41); NOTE 3: “r” is frequently used as a numerical expression for the linear dependence between X and Y in the series of paired observations.


correlation coefficient

(r) a measure of the linear relationship between two random variables;

Project: EP09

NOTE 1: It ranges from −1 to 1, ie, from perfect negative to perfect positive linear relationship; NOTE 2: r = 0 indicates no observed linear relationship.


correlative biomarker

biomarker that provides proof of mechanism or mechanism of action information but is not used for medical decision making in patients who provide the samples.

Project: MM23


corrosive

having the quality of corroding or eating away; erosive (RHUD1.7CD)


corrosive

causing visible destruction of tissue at the site of contact (U.S. 40 CFR 261.22);

NOTE: For solid waste, this term applies to any aqueous material that is highly acidic (pH < 2.0) or highly alkaline (pH > 12.5) (US 40 CFR 261.22) (Cf. GP5).


corrosive

a substance that can cause damage to human skin at the site of contact

Project: QMS04


corrosive

any substance that causes visible destruction of human tissue at the site of contact;

Project: GP05

NOTE: The Environmental Protection Agency (EPA) defines corrosivity as a substance that is highly acidic (pH ≤ 2.0) or highly alkaline (pH ≥ 12.5).


cosmid

a hybrid plasmid that contains a lambda phage cos sequence.

Project: MM09


cost

expenses incurred in the provision of services or goods

Project: GP49, GP45

NOTE 1: Many different kinds of costs are defined and used (see allowable, direct, indirect, and operating costs); NOTE 2: The price of a service or amount billed to an individual or third party may or may not be equal or proportional to service costs.


cost of poor quality

the costs associated with providing poor quality products or services.

Project: QMS20


cost of quality

the total of prevention and appraisal costs and internal and external failure costs related to the quality of a product or service.

Project: QMS20


cost per patient test

the net of any cost associated with consumables, quality control, and calibrators, and includes labor costs; it includes dilution, repeat, and confirmatory testing; NOTE: The cost per reportable patient test is higher than the cost per test. If the 100 test kit costs $1000 and 30 tests are used for quality control and calibration, then the reportable test is $1000/70 patients + labor costs and other consumables.

Project: POCT09


cost-benefit analysis

an analytic method in which a program’s cost is compared to the program’s benefits for a period of time, expressed in dollars, as an aid in determining the best investment of resources

Project: GP45

NOTE 1: For example, the cost of establishing an immunization service might be compared with the total cost of medical care and lost productivity that will be eliminated as a result of more persons being immunized; NOTE 2: Cost-benefit analysis can also be applied to specific medical tests and treatments.


cost-effectiveness analysis

(CEA) 1) This form of analysis seeks to determine the costs and effectiveness of an activity or to compare similar alternative activities to determine the relative degree to which they will obtain the desired objectives or outcomes; the preferred action or alternative is one that requires the least cost to produce a given level of effectiveness, or provides the greatest effectiveness for a given level of cost; 2) a form of analysis that seeks to determine the costs and effectiveness of a medical intervention compared to similar alternative interventions to determine the relative degree to which they will obtain the desired health outcome(s)

Project: GP45

NOTE 1: In the healthcare field, outcomes are measured in terms of health status; NOTE 2: Cost-effectiveness analysis can be applied to any of a number of standards, such as median life expectancy or quality of life following an intervention.


counting beads

fluorescent microspheres of known concentration, which are combined in a known amount with a sample in order to assess the concentration of a population in that sample (eg, lymphocyte subsets, CD34+ hematopoietic stem cells) (H42).

Project: H42


courier service

provider that facilitates the transport of specimens from a referring laboratory to a referral laboratory

Project: QMS05

NOTE: A courier service may be provided by the referral laboratory or may be offered through a third party as part of a separate fee for service arrangement between the referring laboratory and referral laboratory.


covariance

mean of the product of two centred random variables in their joint probability distribution (ISO 3534-1)

Project: ISO 3534


covariance

the covariance of two random variables is a measure of their mutual dependence (JCGM 100:2008 § C3.4)

Project: C51

NOTE: The covariance between two random variables x and y can be symbolized sxy or cov(x,y).


coverage

in massively parallel sequencing, the number of times a given nucleotide or nucleic acid region is represented in sequence reads, with data aggregated to generate a consensus read or sequence;

Project: MM09

NOTE: Depth of coverage is often expressed as a mean number across the full sequence of a sample or for a target nucleic acid region of interest.


coverage factor

number larger than one by which a combined standard measurement uncertainty is multiplied to obtain an expanded measurement uncertainty (JCGM 200:2012)

Project: ISO IEC Guide 99, C53, C51

NOTE: A coverage factor is usually symbolized k (see also ISO/IEC Guide 98-3:2008, 2.3.6) (JCGM 200:2012).


coverage interval

interval containing the set of true quantity values of a measurand with a stated probability, based on the information available (JCGM 200:2012)

Project: ISO IEC Guide 99, C51

NOTE 1: A coverage interval does not need to be centered on the chosen measured quantity value (see ISO/IEC Guide 98-3:2008/Suppl.1) (JCGM 200:2012); NOTE 2: A coverage interval should not be termed "confidence interval" to avoid confusion with the statistical concept (see ISO/IEC Guide 98-3:2008, 6.2.2) (JCGM 200:2012); NOTE 3: A coverage interval can be derived from an expanded measurement uncertainty (see ISO/IEC Guide 98-3:2008, 2.3.5) (JCGM 200:2012).


coverage probability

probability that the set of true quantity values of a measurand is contained within a specified coverage interval (JCGM 200:2012)

Project: ISO IEC Guide 99, C51

NOTE 1: This definition pertains to the Uncertainty Approach as presented in the GUM (JCGM 200:2012); NOTE 2: The coverage probability is also termed "level of confidence" in the GUM (JCGM 200:2012).


coverage threshold

in massively parallel sequencing, the number of reads at which increased coverage is unlikely to improve sequence data quality;

Project: MM09

NOTE: Generally refers to a specifically defined level of coverage or the number of times a given region is resequenced under stated assay conditions


covert incident

an event intrinsically unrecognizable as life threatening at inception

Project: POCT14

NOTE: For example, an infectious bioterrorist attack is usually covert, thus denying the exposed population prophylaxis.


covert incident

event that is not readily detectable or announced;

Project: GP36

EXAMPLE: An infectious bioterrorist attack is usually covert, thus denying prophylaxis to the exposed population; NOTE: A covert incident is classically represented by the dispersal or spread of an infectious agent. It can also pertain to the dispersal of a chemical or radiological agent. Victims occur over time, potentially at many geographically disparate sites. Early incident detection and epidemiology is difficult.


COWT

the “microbiological breakpoint” that separates populations on MIC distributions will be called “wild-type cutoff” and will be abbreviated COWT. It is established solely on the basis of the MIC data associated with the epidemiological database derived from geographically diverse diagnostic laboratory surveys. These isolates are not from animals that were part of a clinical field trial. This estimate is to be used in the establishment of interpretive criteria, as described in Appendix C. It is not intended to be reported to clinical laboratories and will not be published within CLSI documents.

Project: VET02


CQI interface

the important interchange of information between all five functionally interrelated CQI components of quality planning, quality teamwork, quality monitoring, quality improvement, and quality review;

NOTE: By utilizing the quality review component of the QSE: Organization, this interface facilitates the synchronization of all five CQI components.


critical

(services or processes) operations essential to the integrity of the quality management system and to patient care.

Project: GP35


critical concentration

the “critical concentrations” of antituberculous drugs were adopted by international convention;

Project: M24

NOTE: For each drug, the critical concentration is the lowest concentration that inhibits 95% of "wild-type" strains of M. tuberculosis that have not been exposed to the drug, but that simultaneously does not inhibit strains of M. tuberculosis considered resistant that are isolated from patients who are not responding to therapy.


critical control point

(CCP) a point, step, or procedure at which controls can be applied and a hazard or risk can be prevented, eliminated, or reduced to acceptable (critical) levels;

Project: ILA33

NOTE: If the CCP is omitted or not performed adequately, the process may be adversely affected. A function or an area in a manufacturing process or procedure that failure or loss of control may have an adverse effect on the quality of the finished product and may result in a health risk.


critical control point

a point or step in an analytical procedure that is susceptible to an error;

Project: POCT07

NOTE: With the implementation of the right quality control, an error can be mitigated to an acceptable level.


critical control points

(CCPs) groupings of related activities and tasks that must be accomplished effectively to minimize errors in operational processes (HS04).


critical difference

the average difference between reported results from a set of patient samples that corresponds to the limit a laboratory is willing to accept.

Project: EP26


critical equipment

a piece of equipment, material, service, or task that can affect the quality of the facility’s products or services.

Project: ILA33


critical failure

a failure that can initiate a hazard.

Project: POCT07


critical incident stress management

(CISM) a product of the International Critical Incident Stress Foundation, Inc.;

NOTE: ICISF is a nonprofit, open membership foundation dedicated to the prevention and mitigation of disabling stress through the provision of: education, training, and support services for all Emergency Services professions, which also provides consultation in the establishment of Crisis and Disaster Response Programs for varied organizations and communities worldwide. Information is available via: www.icisf.org.


critical limit

a criterion that separates acceptability from unacceptability.

Project: POCT07


critical point

a step in the operation of software that is essential to the quality of the function or task; NOTE: A critical point can influence the behavior of the system’s user or be a system-performed calculation, interpretation, or algorithm.

Project: AUTO13


critical reagents

reagents without which the laboratory could not function or report results

Project: QMS21


critical risk result

a category of quantitative, semiquantitative, or qualitative results of laboratory or anatomic pathology examinations that signify immediate risk of major adverse outcomes. These results need to be actively communicated to responsible caregivers without delay in order to ensure urgent clinical evaluation and medical intervention

Project: POCT04


criticality

relative measure of the consequences of a failure mode and its frequency of occurrences.

Project: EP18

(MIL-STD-1629A. Procedures for Performing a Failure Mode, Effects and Criticality Analysis. 24 November 1980.) NOTE: Combining the consequences (severity) with frequency (probability) gives the same measure as defined in risk.


criticality analysis

procedure by which each potential failure mode is ranked according to the combined influence of severity and probability of occurrence.

(MIL-STD-1629A. Procedures for Performing a Failure Mode, Effects and Criticality Analysis. 24 November 1980.)


crossed

In the design of a multifactor study, the effects of a factor A are said to be crossed with the effects of a factor B if some of the effects of factor A occur with more than one effect of factor B.;

Project: EP05

EXAMPLE: iIf the reagent lots that are studied at each of several sites are common across the sites, then reagent lot is crossed with site. Factors A and B are fully crossed if every effect of factor A occurs with every effect of factor B. See also nested.


cross-hybridization

the hybridization of a probe(s) to more than one chromosomal locus;

NOTE 1: Some probes consistently cross-hybridize with multiple loci because of similar DNA sequences; other probes may cross-hybridize when the hybridization stringencies are not perfect; NOTE 2: Background signals are not cross-hybridized because they are rare, associate with random chromosomal sites, and often do not touch a chromosomal site.


crossover testing

the parallel testing performed on new and existing reagent systems or reagent shipments/lots to define their relationship and determine their acceptability 

Project: POCT04

Inter-measurement procedure (between-measurement procedure) - the difference between the results obtained by two specified measurement procedures.

Of a result - the difference between the result and the true or expected value.

Of an analytical process - the average difference between the results obtained by the analytical process in question under specified conditions of matrix, analyte concentration, etc., and the true or accepted result; synonym for "systematic error."


cross-reactive immunological material

(CRIM) as used in NBS07, the presence in patients with Pompe disease of a mutant acid α-glucosidase (GAA) protein that cross-reacts with antibodies against normal GAA enzyme.

Project: NBS07


cross-reactivity

in immunology, the reaction of an antibody with an antigen other than that which elicited its formation, as a result of shared, similar, or identical antigenic determinants

Project: I/LA20


cross-reactivity

in Immunology, the reaction of an antibody with an antigen other than that which elicited its formation, as a result of shared, similar, or identical antigenic determinants;

Project: LA01, DI01, ILA18, ILA23, ILA28, ILA34

NOTE: Within the context of this document, cross-reactivity has two meanings. First, it refers to a human IgE antibody that binds to an allergenic epitope that is structurally similar to, but not identical with, the molecule that elicited its formation. Cross-reactivity results from shared, similar, or identical allergenic determinants. There are many illustrations of cross-reactive allergen molecules—for example, among the Hymenoptera (vespid) venoms (see allergen section below). Second, cross-reactivity can refer to the degree to which the monoclonal or polyclonal antihuman IgE detection reagents bind to other human immunoglobulin isotypes (IgG, IgA, IgM, IgD).


cross-reactivity

the ability of a drug, metabolite, a structurally similar compound other than the primary measurand, or even an unrelated compound to affect the assay (C52);

NOTE: See the definition of specificity.


cross-reactivity

the ability of a drug, metabolite, a structurally similar compound other than the primary measurand, or even an unrelated compound to affect the measurement procedure

Project: C52

NOTE: See specificity.


cross-sectional study

a type of observational study that examines the relationship between diseases or other health-related characteristics, and other variables of interest as they exist in a defined population at one particular time

Project: GP45

NOTE 1: The presence or absence of disease and the presence or absence of the other variables (or, if they are quantitative, their level) are determined in each member of the study population or in a representative sample at one particular time; NOTE 2: The relationship between a variable and the disease can be examined: (1) in terms of the prevalence of disease in different population subgroups defined according to the presence or absence (or level) of the variables; and (2) in terms of the presence or absence (or level) of the variables in the diseased versus the nondiseased; NOTE 3: Disease prevalence rather than incidence is normally recorded in a cross-sectional study; NOTE 4: The temporal sequence of cause and effect cannot necessarily be determined in a cross-sectional study.


cross-validation

in statistics, the practice of partitioning a sample of data into subsamples, such that analysis is initially performed on a single subsample, while further subsamples are retained “blind” for subsequent use in confirming and validating the initial analysis (MM17).

Project: MM17


cryoglobulin

a mixture of globulins that precipitates when cooled and dissolves when reheated to body temperature.

Project: ILA30


cryopreservative

a liquid, usually tryptic soy broth with glycerol or skim milk, used to preserve an organism during fast freezing.

Project: M50


Cryoquick

any material used to embed tissue for frozen sections.

Project: MM02


cryptic epitope

an antibody binding site that is hidden from the antibody due to the folding of the protein molecule.

Project: ILA29


cryptology

the science that includes both cryptography and cryptanalysis, and sometimes is said to include steganography. (RFC 2828)

Project: AUTO09


C-terminal crosslinking telopeptide of Type I collagen

(CTX) peptides that are formed during collagen degradation, originating from the C-terminal telopeptide of collagen molecules

Project: C48


culture

the intentional growing of microorganisms, such as bacteria or fungi, in a controlled environment, for purposes of identification or other scientific study, or for commercial and/or medicinal use.

Project: M47


culture

the intentional growing of microorganisms (such as bacteria or viruses) or tissues, in a controlled environment, for purposes of identification or other scientific study, or for commercial and/or medicinal use.

Project: M24


culture

the product resulting from the intentional growth of microorganisms.

Project: M47, M24


culture

the set of shared attitudes, values, goals, and practices that characterizes an institution or organization

Project: QMS16


culture

the result of a process by which organisms are intentionally propagated. This includes typical clinical laboratory microorganisms grown in broth, on solid media, or in cell culture;

Project: M29

NOTE: Typical clinical cultures may be classified as either Category A or Category B, depending on the organism concerned and the professional judgment of the shipper.


culture medium

a substance or preparation used for the cultivation and growth of microorganisms or tissue.

Project: M24, M47


cumulative antibiogram

see cumulative antimicrobial susceptibility test data summary.

Project: M39


cumulative antimicrobial susceptibility test data summary

the report generated by analysis of results on isolates from a particular institution(s) in a defined period of time that reflects the percentage of first isolates (per patient) of a given species that is susceptible to each of the antimicrobial agents routinely tested.

Project: M39


cumulative distribution

for any probability distribution, the cumulative distribution represents the set of each ordered value of the variable with its corresponding percentile


cumulative frequency

the number of members of a set of observations having values that are less than or equal to a given value.


customer

person or organization that could or does receive a product or a service that is intended for or required by this person or organization (ISO 9000)

Project: QMS06, QMS19, ISO 9000

EXAMPLES: Consumer, client, end user, retailer, receiver of product or service from an internal process, beneficiary, and purchaser (ISO 9000); NOTE 1: A customer can be internal or external to the organization (ISO 9000); NOTE 2: Employees may be regarded as internal customers.


customer

all components of a health care organization where the IVD device is installed.

Project: AUTO09


customer

organization or person that receives a product or service (modified from ISO 9000)

Project: QMS16, QMS01, QMS14, POCT07, QMS21, QMS15

EXAMPLES: Consumer, client, end user, retailer, beneficiary, purchaser, patient, or health care provider (modified from ISO 9000); NOTE 1: A customer can be internal or external to the organization (ISO 9000); NOTE 2: Employees may be regarded as internal customers; NOTE 3: Staff may be regarded as internal customers; NOTE 4: For the purposes of QMS01, customers can include patients and health care providers, eg, physicians, nurses, staff; NOTE 5: For point-of-care testing (POCT), the patient would be considered a customer, and the doctor, POCT operator, and so on may be regarded as internal customers (modified from ISO 9000).


customer-supplier concept

every internal and external customer is simultaneously receiving and supplying some service or product to or from other individuals in the system;

NOTE: The patient is the ultimate external customer-supplier; the laboratory employee is the primary internal customer-supplier.


cutoff

the test response point below which a qualitative and quantitative test result is determined to be negative and at or above which the result is determined to be positive

Project: C52


cutoff

for a qualitative test, the threshold above which the result is reported as positive and below which the result is reported as negative.

Project: EP12, MM07


cutoff level

See decision level.

Project: EP24


cutoff value

the quantitative value of a measured analyte that is used to decide whether the result is considered above or below a clinical or analytical decision point (usually positive or negative).

Project: ILA23


cutoff value

quantitative value of the analyte that is used as the decision point between a positive and a negative result (MM17).

Project: MM17


cutoff value

the quantitative value of an analyte (eg, the upper limit of a reference interval for a particular analyte) that is used to decide whether the result is above or below a clinical or analytical decision point (ie, usually positive or negative, but may also represent divisions between grades of positivity [eg, weak positive, moderate positive, strong positive]).

Project: H60


cut-point

the response level in the assay that discriminates between the absence and presence of IgE antibody (eg, negative and positive cut-points);

Project: ILA34

NOTE 1: They can be referenced to response reference intervals obtained in the assay using a panel of specimens from a known healthy (nondiseased) population and a known diseased population. Data normalization and outlier removal are issues discussed in the guideline; NOTE 2: See detection limit.


cyanmethemoglobin

hemoglobin in which the iron atoms are in the ferric state and which are bonded with cyanide ions.

Project: H15


cyanobacterium-like body

(CLB) organism thought to be a new pathogen, possibly an oocyst, a flagellate, an unsporulated coccidian, a large Cryptosporidium spp., or a blue green alga and now thought to be coccidia in the genus Cyclospora (Cyclospora cayetanensis).

Project: M28


cycle threshold

(Ct) the Ct value of each RT-PCR reaction depends on the initial template amount (copy number) of the target sequence, and it is inversely proportional to the log of this copy number (MM16);

Project: MM16, MM17

NOTE: In an experiment where all PCR reactions have similar efficiency, the Ct value will be the lowest for reactions where the initial template copy number was highest (MM16).


cycle time components

the identified time segments of the process of moving from one sample to the next, including: presentation of specimen along transportation system to docking site at instrument; identification/recognition that the correct specimen is in place; either direct aspiration from specimen container by probe, or transfer of specimen container to instrument, aspiration, and return of specimen container to specimen carrier/transportation system; departure of completed specimen container; movement into position of next specimen container.

Project: AUTO01, AUTO02


cyst

the nonfeeding encysted stage of the protozoa

Project: M28


cystic fibrosis

an inherited chronic disease affecting primarily the lungs and digestive systems; due to a defective gene and its protein product

Project: NBS05

NOTE: Present in about 30 000 people in the United States and 70 000 worldwide.


cystic fibrosis

hereditary disease prevalent especially in Caucasian populations that appears usually in early childhood, which is inherited as an autosomal recessive monogenic trait and involves functional disorder of the exocrine glands; is marked especially by faulty digestion due to a deficiency of pancreatic enzymes, by difficulty in breathing due to mucus accumulation in airways, and by excessive loss of salt in the sweat (MM17).

Project: MM17


cystic fibrosis carrier

as used in this document, a heterozygote with a mutation in one cystic fibrosis transmembrane conductance regulator (CFTR) allele and one normal or wild-type CFTR allele, such as an infant who had one CFTR mutation identified through immunoreactive trypsinogen (IRT)/DNA screening and then a negative sweat chloride test

Project: NBS05

NOTE: Infants who are CF carriers appear to be free of any signs/symptoms of CF disease, although a small percentage are identified by newborn screening because of a tendency to elevated IRT levels.


cystic fibrosis membrane conductance regulator

a 1480 amino acid protein coded for by a gene located on the long arm of chromosome 7 (q31.2), which is a member of the ABC transporter protein family and acts as a chloride ion channel on the apical surface of secretory epithelial cells

Project: NBS05


cystic fibrosis membrane conductance regulator-related disorders

clinical condition, usually presenting a monosymptomatic disorder in children or adults, that does not meet the diagnostic criteria of cystic fibrosis, but in which there is evidence of CFTR dysfunction

Project: NBS05


cystic fibrosis-causing mutation

a DNA sequence alteration causing cystic fibrosis (CF), if in trans with another CF-causing mutation

Project: NBS05


cytokine flow cytometry

(CFC) a laboratory technique in which the following steps are performed: (1) cells are stimulated to produce cytokines in the presence of protein secretion inhibitors, permitting cytokines to accumulate inside the producing cells; (2) the cells are stained with antibodies for markers on their surface (e.g., anti-CD3, anti-CD4, or anti-CD8), washed, and fixed; (3) the cells are permeabilized, and then stained with the anticytokine antibody, followed by a wash step; and (4) the cells are then analyzed by flow cytometry;

NOTE: This term is synonymous with both intracellular cytokine staining (ICC) and intracellular cytokine flow cytometry (ICFC).


cytomegalovirus

(CMV) most often, use of the term CMV is meant to indicate human CMV, a member of the herpes virus family Herpesviridae;

Project: I/LA26

NOTE 1: The term "HCMV" is sometimes encountered; NOTE 2: Many mammalian species have their own distinct CMVs.


cytomorphology

the subcellular features of a cell;

Project: I/LA28

NOTE: As used in immunohistochemistry, it is the subcellular localization of the antibody-antigen reaction.


cytopathic effect

(CPE) a variety of morphologic changes occurring in monolayered cell cultures as a result of viral infection

Project: M41


cytotoxicity assays

a test based on complement-dependent cytotoxicity;

Project: ILA29

NOTE: When antibody is bound to antigen, complement is activated. The end result of the complement cascade is the membrane attack complex, which disrupts the cell membrane and destroys the cells. The detection of cell death correlates with the presence of specific antibody for the target antigen.


dalton

see unified atomic mass unit.

Project: C50


dangerous goods

materials which, when not properly handled and contained, can pose a risk to the health, safety, property, or environment and are included on the list of dangerous goods in the International Air Transport Association Dangerous Goods Regulations.

Project: M29


data

individual facts, statistics, or items of information, or a body of facts or information (RHUD1.7CD);

NOTE: The term "datum" is sometimes used to describe an individual fact, observation, or number.


data

(continuous) data that can take an infinite number of values (as in categories);

Project: I/LA28

EXAMPLES: Age, height, weight, pulse, and many analytes measured by enzyme-linked immunosorbent assay–type methods; NOTE 1: The data are measured on a continuous scale, with each unit equidistant from the next; NOTE 2: The analytical results from immunohistochemistry assays using formalin-fixed, paraffin-embedded specimens with detection systems using immunoenzyme-based detection systems are not expressed as continuous data.


data

(ordinal) data that are simply ordinal numbers;

Project: I/LA28

NOTE 1: Ordinal scales are frequently used in the grading and scoring systems used in immunohistochemistry, such as 0, 1, 2, 3+. The distance between the ordinal numbers may be traceable to independent quantitative assays, but the distances between the ordinal numbers or symbols are not constant mathematical relationships. For example, 1+ and 2+ do not equal 3+. 3+ minus 1+ does not equal 2+; NOTE 2: Ordinal data are also referred to as semiquantitative data.


data

(categorical) data that are not pure measurements but are in the form of labels assigned, such as “male” and “female”;

Project: I/LA28

NOTE: In immunohistochemistry assays, a categorical result might be expressed as positive or negative (for the presence or absence of a biomarker).


data

(semiquantitative) a test that has a dose-response that may be included in the reported result, but for which no authoritative calibration scale exists to determine the inaccuracy and imprecision;

Project: I/LA28

NOTE: This definition includes tests with subjective readout of quantification such as IF-ANA titers, and it includes tests with an instrumental readout of quantification such as ELISA-ANA, in which the instrument scale cannot be referenced to an authoritative calibration scale. Tests that yield results in an approximate range of values (eg, trace, moderate).


data acquisition board

a device that collects and measures signals from sensors and sends them to a computer for processing.

Project: C39


data confidentiality

the property that information is not made available or disclosed to unauthorized individuals, entities, or processes (i.e., to any unauthorized system entity). (RFC 2828; ISO/IEC 7498-1, 7498-2, 7498-4)

Project: AUTO09


Data Encryption Standard

(DES) a U.S. government standard that specifies the Data Encryption Algorithm and states policy for using the algorithm to protect unclassified, sensitive data. (See: AES.) (RFC 2828)

Project: AUTO09


data integrity

the property that data has not been changed, destroyed, or lost in an unauthorized or accidental manner. (RFC 2828)

Project: AUTO09


Data Manager

(DM) typically, a network server that provides the services of an Observation Reviewer (e.g., POC data storage and forwarding, QA/QC, and other POC instrument and data management functions);

Project: POCT01

NOTE 1: In addition to these services, Data Managers usually provide other applications or services tailored to particular devices or POC user needs (such as regulatory reporting and operator management applications); NOTE 2: Data Manager systems are specific instances of Observation Reviewer services.


data manager

(DM) typically, a manufacturer-specific network server or more general computer system that acts as an observation reviewer to provide collection of POC data and storage of data, and communication of data, QA/QC, and other POC instrument and data management functions (CLSI document POCT02);

Project: POCT02

NOTE: In addition to these functions, data managers usually provide other applications or services tailored to specific devices or POC user needs (such as management of operators, reagent lot numbers/expiration dates, and reports for regulatory compliance) (CLSI document POCT02).


Data Manager Interface

(DMI) specifies the TCP/IP network interface and protocol between a Data Manager and one or more Access Points.

Project: POCT01


data reduction algorithm

a mathematical process that converts assay-response data (eg, counts per minute−bound, absorbance, fluorescence, chemiluminescence, or surface Plasmon resonance units) into interpolated dose results

 

Project: I/LA20

NOTE: The dose-response relationship in the assay is defined by the standard, refere or calibration curve.


dataset

a set of minimal inhibitory or minimal effective concentration data generated in a single laboratory

Project: M57


datum error

measurement error of a measuring instrument or measuring system at a specified measured quantity value (JCGM 200:2012)


datum measurement error

measurement error of a measuring instrument or measuring system at a specified measured quantity value (JCGM 200:2012)

Project: ISO IEC Guide 99


daughter tube

See aliquot container.

Project: AUTO12


dead band

maximum interval through which a value of a quantity being measured can be changed in both directions without producing a detectable change inthe corresponding indication (JCGM 200:2012)

Project: ISO IEC Guide 99

NOTE: Dead band can depend on the rate of change (JCGM 200:2012).


dead band

maximum interval through which a value of aquantity being measured can be changed in both directions without producing a detectable change in the corresponding indication (JCGM 200:2012)

NOTE 1: The dead band may depend on the rate of change; NOTE 2: The dead band is sometimes deliberately made large to prevent change in the response for small changes in the stimulus.


dead space volume

the volume of blood that would fill the length of a catheter lumen (H21);

Project: H21

NOTE: This term is used in the collection of blood from indwelling vascular access devices (H21).


dead volume

the retention volume of a container above which aspiration and dispense can be performed reliably.

Project: ILA33


dead-end corridor

route that exceeds a specified length that does not lead to a fire exit

NOTE: Lengths are determined by fire codes for a specific building type.


deadleg

a region or volume of stagnation in an apparatus or distribution system

Project: GP40


deadspace ratio

the ratio of physiologic deadspace (and instrument deadspace, if applicable) to tidal volume. (Cf. C12).

Project: C12


decadic absorbance

the negative decadic logarithm of one minus the absorptance.


decapper

part of an automation line at which the caps are taken off the specimen container


decapping

the removal of a closure from a specimen container.

Project: AUTO02


decedent

legal and general term meaning a person who has died.

Project: GP36


decision analysis

a derivative of operations research and game theory that involves identifying all available choices, and potential outcomes of each, in a series of decisions that have to be made about aspects of patient care—diagnostic procedures, therapeutic regimens, and prognostic expectations

Project: GP45

NOTE 1: Epidemiologic data play a large part in determining the probabilities of outcomes following each choice that has to be made; NOTE 2: The range of choices can be plotted on a decision tree, and at each branch or decision node, the probabilities of each outcome that can be predicted are displayed; the decision tree thus portrays the choices available to those responsible for patient care and the probabilities of each outcome that will follow the choice of a particular action or strategy in patient care; NOTE 3: The relative worth of each outcome is preferably described as a utility or quality of life, e.g., a probability of life expectancy or freedom from disability, often expressed as quality adjusted life years (QALYs).


decision level

a test value or statistic that marks the upper (or lower) boundary between a negative (normal) or acceptable result and a positive (abnormal) or unacceptable result (Cf. GP10).

Project: GP10


decision level

a test value or statistic that marks the upper (or lower) boundary between diagnostic categories, ie, between negative (acceptable or unaffected) results and positive (unacceptable or affected) results.

Project: EP24


decision matrix

(prioritization matrix) evaluates and prioritizes a list of options;

Project: QMS14

NOTE 1: A list of weighted criteria is established, then each option is evaluated against those criteria; NOTE 2: A decision matrix is used when a list of options must be narrowed to one choice; when the decision must be made on the basis of several criteria; or after the list of options has been reduced to a manageable number by list reduction (adapted from ASQ).


decision point

(medical decision point) a concentration of the measurand that is used as a threshold for making a clinical statement;

Project: EP09

NOTE: Often, decision points will refer to reference limits, but other concentrations, such as from clinical guidelines, are also used.


decision point

See decision level.

Project: EP24


decision threshold

See decision level.

Project: EP24


decontamination

procedure that eliminates or reduces microbial or toxic agents to a safe level with respect to the transmission of infection or other adverse effects (ISO 15190)

Project: QMS04, ISO 15190, M29

NOTE 1: Some disinfectants can be used for decontamination. These are intermediate or low-level disinfectants and in the United States, are regulated by the US Environmental Protection Agency for use on inanimate surfaces. They should not be used on medical devices that are used on patients; likewise, liquid chemical germicides formulated as sterilants or high-level disinfectants ordinarily are not used for purposes of decontamination because of the risk to personnel.


decontamination

for infectious waste, a procedure that eliminates or reduces microbial contamination to a safe level with respect to the transmission of infection;

Project: GP05

NOTE: Sterilization and disinfection procedures are often used for decontamination of infectious waste; other procedures are available for chemical and radioactive material decontamination. See infectious waste.


deconvolution

a process of mathematically resolving something into its constituent components (CLSI document C50);

Project: C50

NOTE: It is applied to the separation of multiple charged spectra and/or chromatograms into their individual components (CLSI document C50).


decreased susceptibility

describes isolates with minimal inhibitory concentrations that are non–wild type but less than or equal to the susceptible clinical breakpoint.

Project: VET05, VET04


dedicated circuit

an independent electrical connection devoted to a specific piece of equipment

Project: QMS04


deep sequencing

multiple sequence determinations of a single base or across a genomic region during analysis; implies high depth of coverage in massively parallel sequencing.

Project: MM09


deep vein thrombosis

(DVT) an intravenous thrombus in a deep vein, usually in the proximal legs or pelvis, but may also occur in an upper extremity.

Project: H59


deep venous thrombosis

See deep vein thrombosis.


deep-seated lesion

situated in the thoracic or abdominal organ/cavity;

Project: GP20

NOTE: It is usually not palpable and is visualized radiologically.


deep-seated mass

See deep-seated lesion.

Project: GP20


definitional uncertainty

component of measurement uncertainty resulting from the finite amount of detail in the definition of a measurand (JCGM 200:2012)

Project: ISO IEC Guide 99, C51

NOTE 1: Definitional uncertainty is the practical minimum measurement uncertainty achievable in any measurement of a given measurand (JCGM 200:2012);NOTE 2: Any change in the descriptive detail leads to another definitional uncertainty (JCGM 200:2012); NOTE 3: In the ISO/IEC Guide 98-3:2008, D.3.4, and in IEC 60359, the concept ‘definitional uncertainty’ is termed "intrinsic uncertainty" (JCGM 200:2012).


definitive method

(DM) an analytical method that has been subjected to thorough investigation and evaluation for sources of inaccuracy, including nonspecificity;

Project: NRSCL8

NOTE 1: The magnitude of the DM’s final imprecision and bias, expressed in the uncertainty statement, is compatible with the DM’s stated end purpose; NOTE 2: The mean DM value is taken as the "true" value (Cf. NRSCL13).


definitive testing

a procedure that is based on a different, more specific, physicochemical method than the original screening assay, and is used to confirm positive results; definitive tests can be qualitative or quantitative

Project: C52

NOTE: A definitive test determines whether a specimen result is ultimately reported as positive or negative. Mass spectrometric techniques and other similar technologies are generally used for definitive testing.


degradation

the natural (hydrolysis), accidental (poor handling procedures), or induced (nuclease) destruction of a molecule into its component parts; especially as pertains to RNA integrity and stability.

Project: MM13


de-identification

de-identification – the removal of names and other explicit identifiers from personal records;

Project: AUTO11

NOTE 1: Under the Health Insurance Portability and Accountability Act (HIPAA) Privacy Rule, data are de-identified if either: 1) an experienced expert/qualified statistician determines the risk that certain information could be used to identify an individual is “very small,” and documents as well as justifies the determination; or 2) the data do not include any of the following 18 identifiers (of the individual or his/her relatives, household members, or employers) that could be used alone or in combination with other information to identify the subject: names; geographic subdivisions smaller than a state (including zip code); all elements of dates except year (unless the subject is greater than 89 years old); telephone numbers; fax numbers; e-mail address; Social Security numbers; medical record numbers; health plan beneficiary numbers; account numbers; certificate/license numbers; vehicle identifiers including license plates; device identifiers and serial numbers (patient care devices); URLs; Internet protocol addresses; biometric identifiers (fingerprint, retina scan); full face photos and comparable images; any unique identifying number, characteristic, or code; NOTE 2: Even if the above identifiers are removed, the HIPAA Privacy Rule states that information will be considered identifiable if the covered entity knows that the identity of the person may still be determined.


deidentify

use of a system that would create a new index that would relate to the patient;

Project: AUTO09

NOTE: This value would be sent in the data to the vendor. If information about a patient sample was required, the issuing institution would look up the information using this value. With this system, all the patient information would reside solely in the healthcare facility.


deionization

the removal of ions from a solution by ion exchange (ASTM8) (Cf. C3)

Project: ASTM08


deionized water

(DI) water resulting from the removal of ionized minerals and salts by ion exchange

Project: QMS04


deletion

loss of one or more nucleotides from a nucleic acid sequence.

Project: MM18, MM22


deletion

the loss of DNA sequence from a chromosome;

Project: MM19

NOTE: The deleted DNA may be of any length from a single base to a large part of a chromosome.


delimiter

1) a symbol used to separate items in a list; 2) in software data management, a bit, character, or set of characters used to denote the beginning or end of a group of related bits, characters, words, or statements. For example, the ampersand (&) in the character string "& APPLE &" (IEEE 610.5, 610.12).

Project: AUTO01, AUTO02, AUTO03


delta change

a change within a specified time frame between two consecutive examination results of the same measurand

Project: GP47


delta check

a comparison of two consecutive results from a patient, based on specified criteria, as a quality improvement effort by the laboratory.

 

Project: EP33


delta check alerts

refer to situations in whichdifferences between consecutive results exceed a specified delta check limit.

Project: EP33


dematiaceous

(phaeoid) having conidia, spores, or hyphae that are brown to black in color due to the presence of melanin.

Project: M54


Deming regression

a method to estimate slope and intercept parameters from a measurement procedure comparison experiment with allowance for both measurement procedures to have imprecision;

Project: EP09, EP14

NOTE: The measurement error for each measurement procedure is accounted for in the estimation procedure.


demolition

wrecking or removal of existing building components to allow new construction


demonstration

(study) a study performed by a laboratory to show that it is capable of using a test system to obtain expected performance;

Project: I/LA28

NOTE: Laboratories may conduct a demonstration study when they are considering the logistical decision about whether to purchase an immunohistochemistry assay or its components.


denaturation

the conversion of double-stranded DNA or RNA to a single-stranded state with minimal secondary structure;

Project: MM09, MM01

NOTE 1: This is done by heating, increasing pH, or adding agents such as formamide or urea; NOTE 2: Once denatured, nucleic acid molecules are available for hybridization with a primer or probe.


denaturation

(protein) disruption of the native structure of a protein molecule either with chemicals, such as acid, base, or detergents, or with heat.

Project: ILA29


denaturation

1) loss of native structure or configuration of a macromolecule, usually with resulting loss of biological or immunological reactivity or solubility (Cf. I/LA15); 2) the conversion of double-stranded DNA or RNA to a single-stranded state with minimal secondary structure;

Project: MM10, MM12

NOTE: This is done by heating, increasing the pH, or adding agents such as formamide or urea; once denatured, nucleic acid molecules are available for hybridization with a primer or probe.


dendrogram

a branching, tree-like diagram that illustrates the hierarchical relationships among items in a dataset (MM18).

Project: MM18


denial of service

(DoS) the prevention of authorized access to a system resource or the delaying of system operations and functions. (RFC 2828)

Project: AUTO09


deoxypyridinoline

(DPD) pyridinium compound formed during collagen maturation by crosslinking lysine and hydroxylysin side chains from different collagen molecules

Project: C48


deoxyribonuclease

any enzyme that catalyzes the hydrolytic cleavage of phosphodiester linkages in the DNA backbone;

Project: MM19

NOTE: A wide variety of deoxyribonucleases are known, which differ in their substrate specificities, chemical mechanisms, and biological functions.


deoxyribonucleic acid

(DNA) a type of nucleic acid; a polynucleotide having a specific sequence of deoxyribonucleotide units principally serves as the carrier of genetic information (H21).

Project: H21


deoxyribonucleic acid

(DNA) a type of nucleic acid; a polynucleotide having a specific sequence of deoxyribonucleotide units (dNTPs) and serving as the carrier of genetic information (MM02);

Project: MM02, MM13, MM17

NOTE: DNA is a double-stranded molecule held together by weak hydrogen bonds between base pairs of nucleotides. The four nucleotides in DNA contain the bases adenine (A), guanine (G), cytosine ©, and thymine (T). Essentially, two forms of DNA can be distinguished: genomic DNA (Gdna) from the nucleus (nuclear DNA of the chromosomes), and mitochondrial DNA (MM02).


depletion analysis

a procedure used to estimate the quantity of IgE antibody in the calibration process of a prospective reference serum by removal of specific IgE and detection of changes in total IgE levels.

Project: ILA34


depletion analysis

a procedure used to estimate the quantity of IgE antibody in the calibration process of a prospective reference serum

Project: I/LA20

NOTE: This technique has not been widely used for estimating the quantity of immunoglobulin G, immunoglobulin A, or immunoglobulin M antibody of defined antigen specificities in other prospective reference sera because the percentage of the total immunoglobulin of these isotypes that is specific antibody directed to a particular antigen is low generally in comparison to the percentage of Immunoglobulin E (IgE) that is specific for one allergen. This leads to inaccuracies that prevent the successful use of this method in calibrating reference sera. Using short ragweed as an illustrative allergen specificity, a potent IgE antiragweed containing serum is first optimally preabsorbed with either ragweed-solid phase or a sham-solid phase. Three sera (unabsorbed, sham-absorbed, and ragweed-absorbed) are then analyzed in a total serum IgE for their IgE content. Difference in the total IgE levels between the sham- and ragweed-absorbed serum represents the amount of specific IgE that was depleted or removed from the serum by the solid-phase allergen. The sham-adsorbed IgE antibody levels should be equivalent to unabsorbed serum levels. Elution of the ragweed-solid phase adsorbed IgE antibody can be added to the procedure to validate the efficiency of the extraction procedure and provide an additional level of confidence in the specific antibody estimation.


depth of coverage

see coverage.

Project: MM09


derivative

the instantaneous rate of change of a function, defined as the limit of the rate of change over a time interval Δt when Δt tends to zero. For example, the derivative G' (t) = limΔt→0 ΔG÷Δt represents the instantaneous rate of change of glucose fluctuation at time t (POCT05).

Project: POCT05


derivative tube

See aliquot container.

Project: AUTO12


derivatization

selective chemical alteration of analyte functional groups

Project: NBS04

NOTE 1: Derivatization is usually performed to improve sensitivity, selectivity, or retention characteristics; NOTE 2: In the case of newborn screening, the carboxylic acid functional groups are most often converted to butyl esters.


derived quantity

quantity, in a system of quantities, defined in terms of the base quantities of that system (JCGM 200:2012)

Project: ISO IEC Guide 99

EXAMPLE 1: In a system of quantities having the basequantities length and mass, mass density is a derivedquantity defined as the quotient of mass and volume(length to the third power) (JCGM 200:2012). EXAMPLE 2: In a system having base quantities length, mass, and time, velocity is a derived quantity defined as length divided by time.


derived unit

measurement unit for a derived quantity (JCGM 200:2008);

Project: ISO IEC Guide 99

EXAMPLES: The metre per second, symbol m/s, and the centimetre per second, symbol cm/s, are derived units of speed in the SI. The kilometre per hour, symbol km/h, is a measurement unit of speed outside the SI but accepted for use with the SI. The knot, equal to one nautical mile per hour, is a measurement unit of speed outside the SI (JCGM 200:2012).


derived unit

(of measurement) unit of measurement of a derived quantity in a given system of quantities (VIM93-1.14);

NOTE: Some derived units have special names and symbols; for example, in the SI:

Quantity

SI derived unit

Name

Symbol

force

energy

pressure

newton

joule

pascal

N

J

Pa

 


dermatophyte

a fungus that obtains nutrients from keratin and infects skin, hair, and nails; consists of species within the genera Microsporum, Trichophyton, and Epidermophyton.

Project: M54


descriptive safety

the requirements and procedures for installation, use, and monitoring of medical devices to ensure their continued safety (ISO Guide 63-2.3).

Project: ISO Guide 63-2.3


design

product development stage in which considerations may include whether the measurement procedure would be better than existing measurement procedures, and whether it would meet a clinical need that is not currently met (or better meet the need in terms of speed, cost, sensitivity, specificity, etc.);

Project: EP19

NOTE 1: The intended use for testing patients is agreed upon during the design stage; NOTE 2: Relevant system specifications may be established during the design stage. During development, the measurement procedure is iteratively optimized to meet these specifications.


design controls

the interrelated set of practices and procedures that are incorporated into the design and development process, ie, a system of checks and balances;

Project: I/LA28

NOTE: Design controls make systematic assessment of the design an integral part of development. As a result, deficiencies in design input requirements and discrepancies between the proposed designs and requirements are made evident and corrected earlier in the development process. Design controls increase the likelihood that the design transferred to production will translate into a device that is appropriate for its intended use.


design development

(DD) third design phase of a construction project, in which the plans generated in the previous phase (schematic design) are drawn in greater detail, more engineering information is incorporated, and the elevations are generated

Project: QMS04


design input requirements

the physical and performance requirements of a device that are used as a basis for device design.

Project: EP25


designated comparison method

DCM, a fully specified method(s), which, in the absence of an NRSCL-credentialed reference method, serves as the common basis for the comparison of “field” reference materials and methods, and for the development of principal assigned values (PAVs) or principal assigned characteristics (PACs) for an analyte or process.

Project: NRSCL13, C44


desk assessment

documentation audit performed at a desk using the audited organization’s quality management system documentation.

Project: QMS15


desktop audit

See desk assessment.

Project: QMS15


detectability

the ability of an analytical method to detect small quantities of the component (IFCC-1978-QC Terminology).


detection capability

signaling presence of a measurand in a sample;

Project: EP19, EP19

NOTE: The term “sensitivity” and its variants “analytical sensitivity” and “functional sensitivity” are not used in EP19, because of the existence of several conflicting common uses of these terms across multiple technical disciplines. “Limit of detection” is the preferred term for the detection capability attribute previously associated with analytical sensitivity because of its more precise definition and common use. Similarly, “limit of quantitation” is the preferred term for the detection capability attribute previously associated with functional sensitivity (ie, denoting quantitative detection of a measurand in a sample with known measurement accuracy).


detection limit

measured quantity value, obtained by a given measurement procedure, for which the probability of falsely claiming the absence of a component in amaterial is β, given a probability α of falsely claiming its presence (JCGM 200:2012)

Project: NBS07, NBS04, C52

NOTE 1: IUPAC recommends default values for α and β equal to 0.05 (JCGM 200:2012); NOTE 2: The abbreviation LOD is sometimes used (JCGM 200:2012); NOTE 3: The term "sensitivity" is discouraged for ‘detection limit’ (JCGM 200:2012); NOTE 4: Also called “limit of detection,” “minimum detectable concentration” (or dose or value), and “detection limit”; sometimes used to indicate “analytical sensitivity.”


detection limit

the lowest concentration of analyte that can be reported to be present at a specified level of confidence, often taken to be the analyte concentration that reports a signal three standard deviations above the background.

Project: MM12


detection limit

See limit of detection.


detection limit

the smallest quantity of an analyte that can be reproducibly and statistically distinguished from the background (including variation in background), or a zero calibrator in a given assay system;

Project: ILA34

NOTE 1: It is usually defined at the 95% confidence interval and has also been called the lower detection limit or positive threshold of the assay; this term is not synonymous with analytical sensitivity; NOTE 2: Assuming an adequate number of samples and that their distributions are similar, an equivalent distribution between the 0 calibrator and low positives, the 95% confidence interval means 1.645 standard deviations between the mean levels produced by the 0 calibrator and the low positives. The positive cutoff level should, therefore, be greater than 1.645 SD from the mean of the 0 calibrator. See CLSI document EP17.


detection mechanism

means or methods by which a failure can be discovered by an operator under normal system operation or can be discovered by the maintenance crew by some diagnostic action.

(MIL-STD-1629A. Procedures for Performing a Failure Mode, Effects and Criticality Analysis. 24 November 1980.)


detection rate

(DR) proportion of affected individuals with positive test results.

Project: ILA25


detector

device or substance that indicates the presence of a phenomenon, body, or substance when a threshold value of an associated quantity is exceeded (JCGM 200:2008);

Project: ISO IEC Guide 99

EXAMPLES: Halogen leak detector, litmus paper (JCGM 200:2012); NOTE 1: In some fields, the term "detector" is used for the concept of sensor (JCGM 200:2012); NOTE 2: In chemistry, the term "indicator" is frequently used for this concept (JCGM 200:2012).


detector

device or substance that indicates the presence of a phenomenon without necessarily providing a value of an associated quantity (VIM93-4.15); EXAMPLES a) halogen leak detector; b) litmus paper.

Project: VIM93

NOTE 1: An indication may be produced only when the value of the quantity reaches a threshold, sometimes called the "detection limit" of the detector; NOTE 2: In some fields, the term "detector" is used for the concept of "sensor."


determinant

a determining agent or factor.

Project: NRSCL8


determinant

an algebraic expression of the sum of products of elements, each with an appropriate algebraic sign, usually written in a square array and used in the solution of systems of linear equations.


determinant

archaic, a gene


determinant

See and use epitope or antigenic determinant.


determination coefficient

(r2) see correlation coefficient.

Project: EP09


development

stage of the establishment of a new measurement procedure transitioning from initial conception through systematic improvements in hardware, software, reagents, and other system design elements, to optimize performance to meet specifications.

Project: EP19


deviation

value minus its reference value


device

an instrument (measuring system) that gives analytical answers as a result of electrical or mechanical measurements on an element, compound, solution, etc.

Project: POCT04, AUTO01, AUTO02, EP10, AUTO03, POCT07

NOTE 1: The measurement is often made before and after a chemical or physical reaction; the resultant measurement can be applied to give a final analytical result (EP10); NOTE 2: Device is a term that represents a range of diagnostic instruments deployed in POCT. Devices may include but are not limited to small portable or semiportable systems, benchtop analyzers, handheld devices, and single-use test kits having built-in readers as part of the consumable. 2) any device or combination of devices used for the diagnosis or treatment of injury, or temporary or permanent physical disability, which does not achieve its effect by chemical means, although it may be used in combination with a substance that does (ISO Guide 63-2.9); 3) any medical device which is a reagent, reagent product, calibrator, control material, kit, instrument, apparatus, equipment or system, whether used alone or in combination, intended by the manufacturer to be used in vitro for the examination of specimens, including blood and tissue donations, derived from the human body, solely or principally for the purpose of providing information concerning congenital abnormality, or to determine the safety and compatibility with potential recipients, or to monitor therapeutic measures; 4) in Automation, a unit to prepare specimens for analysis, or to handle specimens after they have been analyzed by another instrument, eg, automated centrifuges, automated aliquoters, automated storage, and retrieval; NOTE 3: In point-of-care testing, the term represents a range of diagnostic systems that may include, but are not limited to, small portable or semiportable systems, benchtop analyzers, handheld devices, cassettes, and single-use test kits having built-in readers as part of the consumable.


Device and Access Point interface

(DAP) specifies the interface between a device and an Access Point or concentrator.

Project: POCT01


device and access point interface

(DAP) specifies the interface or communication connection between a device and an access point (POCT02).

Project: POCT02


Device Communication Controller

(DCC) specifies the interface (principally output) of a POC Device or its Docking Station to an Access Point;

Project: POCT01

NOTE: This is an IEEE definition, equivalent to ‘PDI.’


device end user

end user in the health care organization familiar with the medical device and its operation.

Project: AUTO11


Device Messaging Layer

(DML) the DML describes a complete messaging protocol (message types and message flow) to exchange results and quality information (quality assurance and quality control) between a Device and an Observation Reviewer;

Project: POCT01

NOTE: This protocol may sit on top of any robust, reliable transport, such as the one described by the POCT1 Device and Access Point specification.


Dextramer

(or the equivalent) see MHC Dextramer® (or the equivalent).

Project: I/LA26


diagnostic accuracy

the ability of a diagnostic test to discriminate between diseased and nondiseased subjects, or between two or more clinical states;

Project: EP24, POCT13, EP19

NOTE: For example, discrimination between rheumatoid arthritis and systemic lupus erythematosus.


diagnostic accuracy

the extent of agreement between the information from the test under evaluation and the diagnostic accuracy criteria

Project: EP12, M55

NOTE 1: Diagnostic accuracy can be expressed in different ways, including sensitivity-specificity pairs, likelihood ratio pairs, and the area under a receiver operating characteristic curve; NOTE 2: Diagnostic accuracy must be interpreted in context with the condition of interest and the combination of specific criteria and methods used; NOTE 3: Diagnostic accuracy is not the same as accuracy, which is the closeness of a single result of a measurement and a true value.


diagnostic accuracy

the ability of a test system to obtain the correct result.

Project: MM03, MM22


diagnostic accuracy criteria

the best currently available criteria for establishing the presence or absence of the condition, event, or characteristic of interest using a single method or combination of methods including laboratory tests, imaging tests, pathology, and clinical information including follow-up (EP12);

Project: EP12

NOTE 1: The diagnostic accuracy criteria will evolve with the advancement of analytical systems, and may in a given situation be different from diagnostic accuracy criteria so determined by a regulatory or metrology agency (EP12); NOTE 2: Diagnostic accuracy criteria do not consider the outcome of the candidate test (new test under evaluation). Diagnostic accuracy criteria can be an algorithm specifying the choice and ordering of a combination of methods and how the different results are combined to make a final positive/negative classification (EP12).


diagnostic sensitivity

the proportion of patients with a well-defined clinical disorder (or condition of interest) whose test values are positive or exceed a defined decision limit (ie, a positive result and identification of the patients who have a disease);

Project: MM10, MM12, C50, MM17, EP18, I/LA28, MM19, MM01, MM14, MM22, H60, MM03, MM23

NOTE 1: The clinical disorder must be defined by criteria independent of the test under consideration; NOTE 2: The term "diagnostic sensitivity" (Europe) is equivalent to "clinical sensitivity" (United States); NOTE 3: It is the fraction of clinically true-positive classifications divided by the sum of clinically true-positive and clinically false-negative classifications; NOTE 4: The probability (P) that the test is positive (T+), given that the subject being tested is disease/state positive (D+), ie, P (T+|D+); or, the ability of a test under study to give a positive result for subjects having the disease/state in question; NOTE 5: For the purposes of this document, a more practical definition relates to the signal-to-noise ratio (C50); NOTE 6: The term sensitivity is often used as a synonym for the lowest concentration of an analyte that can be distinguished from background (C50); NOTE 7: The clinical disorder should be defined by criteria independent of the test under consideration; NOTE 8: In Europe, the term “clinical” applies mostly to clinical studies of drugs, under much more stringent conditions.


diagnostic sensitivity

the ability of a measurement procedure to give a positive result for subjects who have the disease or condition for which they are being measured

Project: EP33, I/LA20

NOTE: In the context of EP33, diagnostic sensitivity refers to the ability of a particular delta check rule to detect patient specimens that have identification or integrity issues, or to detect clinically important changes in patient conditions.


diagnostic sensitivity

the probability (P) that the test is positive (T+), given that the subject being tested is disease positive (D+), ie, P(T+|D+); or, the ability of a test under study to give a positive result for subjects having the disease in question

Project: M55


diagnostic sensitivity

as used in I/LA20, the ability of a test to identify the presence of allergen-specific immunoglobulin E (IgE) antibody in samples of patients who are defined by clinical criteria and/or other sensitization (eg, skin test or another laboratory) tests as having a relevant allergy

NOTE: This term is also defined as the proportion of patients known to be allergic with applicable allergen specificities whose test values are positive or exceed a defined decision limit. Allergen-specific IgE can be measured by testing a panel of serum samples from subjects with a positive history of allergic disease and objective evidence of IgE antibody positivity by an alternative accepted method such as skin testing, provocation testing, and/or an accepted reference serology method (provided its diagnostic sensitivity and specificity are known). The serum panel should reflect patients from a variety of allergic disease states relevant to that allergen specificity.


diagnostic sensitivity

the proportion of patients with a well-defined clinical disorder whose test values are positive or exceed a defined decision limit, ie, a positive result and identification of the patients who have a disease (disorder, or condition [POCT05]);

Project: ILA23, POCT05

NOTE 1: The clinical disorder (eg, hypoglycemia or hyperglycemia [POCT05]) must be defined by criteria independent of the test under consideration; NOTE 2: The European term "diagnostic sensitivity" is equivalent to the US term "clinical sensitivity"; NOTE 3: It is the fraction of clinically true positives divided by the sum of clinically true-positive plus clinically false-negative classifications; NOTE 4: In Europe, the term "clinical" applies mostly to clinical studies of drugs, under much more stringent conditions; NOTE 5: For purposes of CGM, diagnostic sensitivity refers to effectiveness of detection of hypoglycemia or hyperglycemia. Sensitivity = TP/(TP+FN) (POCT05).


diagnostic sensitivity

1) as used in CLSI document I/LA02, the ability of a test to correctly identify samples in which ANA are present; 2) as used in CLSI document I/LA34, the ability of a test to correctly identify samples in which allergen-specific IgE antibody is present; it correlates the presence of allergen-specific IgE antibody in the serum of patients who are defined by clinical criteria and/or designated reference laboratory tests as truly allergic;

Project: ILA02, ILA34

NOTE 1: Sensitivity for ANA is ideally determined by testing a panel of serum samples previously determined to be positive for ANA by an accepted reference method or consensus evaluation. This serum panel should reflect samples from a variety of disease states in which ANA are found; NOTE 2: Sensitivity for IgE antibody is ideally determined by testing a panel of serum samples from subjects with a positive history of allergic disease and evidence of IgE antibody positivity by an alternative accepted method such as skin testing, provocation testing, and/or an accepted reference serology method (provided its sensitivity and specificity are known). The serum panel should reflect patients from a variety of allergic disease states relevant to that allergen specificity as well as healthy nonatopic controls.


diagnostic sensitivity

See clinical sensitivity.

Project: M53, NBS05


diagnostic sensitivity

the proportion of patients with a well-defined clinical disorder whose test values are positive or, as in the case with the lamellar body count, below a defined decision limit (ie, a positive result and identification of the patients who have a disease);

Project: C58

NOTE 1: The clinical disorder must be defined by criteria independent of the test under consideration; NOTE 2: The term "diagnostic sensitivity" (Europe) is equivalent to "clinical sensitivity" (United States).


diagnostic sensitivity

the ability of a measurement procedure under study to give a positive result for subjects having the disease/target condition in question;

Project: EP19

NOTE: Formerly, the term clinical sensitivity was used in CLSI documents.


diagnostic sensitivity

as used in this guideline, the ability of a test to correctly identify samples in which allergen-specific IgE antibody is present; it correlates the presence of allergen-specific IgE antibody in the serum of patients who are defined by clinical criteria and/or designated reference laboratory tests as truly allergic;

Project: ILA34

NOTE: Sensitivity for IgE antibody is ideally determined by testing a panel of serum samples from subjects with a positive history of allergic disease and evidence of IgE antibody positivity by an alternative accepted method such as skin testing, provocation testing, and/or an accepted reference serology method (provided its sensitivity and specificity are known). The serum panel should reflect patients from a variety of allergic disease states relevant to that allergen specificity as well as healthy nonatopic controls.


diagnostic sensitivity

as used in ILA20, the ability of a test to correctly identify samples in which allergen-specific IgE antibody is present; it correlates the presence of allergen-specific IgE antibody in the serum of patients who are defined by clinical criteria and/or gold standard laboratory tests as truly allergic;

NOTE: Sensitivity for IgE antibody is ideally determined by testing a panel of serum samples from subjects with a positive history of allergic disease and evidence of IgE antibody positivity by an alternative accepted method such as skin testing, provocation testing, and/or an accepted reference serology method (provided its sensitivity and specificity are known). The serum panel should reflect patients from a variety of allergic disease states relevant to that allergen specificity as well as healthy nonatopic controls.


diagnostic specificity

as used in CLSI document I/LA02, the ability of a test to correctly identify samples in which ANA are absent;

Project: ILA02

NOTE: Specificity for ANA is ideally determined by testing a panel of serum samples previously determined to be negative to ANA by an accepted reference method or consensus evaluation. This serum panel should reflect samples from a variety of disease states as well as normal samples (I/LA02).


diagnostic specificity

the proportion of subjects who do not have a specified clinical disorder (or condition of interest) whose test results are negative or within the defined decision limit;

Project: MM03, ILA21, ILA23, MM10, MM12, C50, POCT05, MM17, I/LA28, MM19, MM01

NOTE 1: It is the fraction of clinically true-negative classifications divided by the sum of clinically true-negative plus clinically false-positive classifications; NOTE 2: This term is equivalent to the US term "clinical specificity"; NOTE 3: In laboratory testing, the ability of a test to give a negative result for patients who do not have the disease or condition for which they are being tested. It is measured as the ratio of negative tests to the total number of tests in those who do not have the disease or condition, and expressed as a percentage; NOTE 4: In Europe, the term "clinical" applies mostly to clinical studies of drugs, under much more stringent conditions; NOTE 5: Diagnostic sensitivity pertains to test results rather than analytical measurements (C50); NOTE 6: For purposes of CGM, diagnostic specificity refers to effectiveness of detection of the absence of hypoglycemia or hyperglycemia. Specificity = TN/(TN+FP) (POCT05); NOTE 6: The probability (P) that the test is negative (T−), given that the subject being tested is disease free (D−), ie, P(T− | D−); or, the ability of a test under study to give a negative result for subjects not having the disease in question.


diagnostic specificity

as used in I/LA20, the ability of a test to correctly identify samples from subjects without clinical allergic symptoms by means of no detectable allergen-specific immunoglobulin (IgE) antibodies; this term is also defined as percent negativity in samples from nonatopic subjects

NOTE: Specificity for IgE antibody is ideally determined by testing a panel of serum samples from 1) nonatopic subjects with a total IgE < 20 kU/L, or 2) subjects with no history of allergic symptoms, or 3) evidence of the absence of IgE antibody positivity by an alternative accepted method such as skin testing, provocation testing, and/or an accepted reference serology method (provided its diagnostic sensitivity and specificity are known). Approaches 1) and 3) will lead to presumably arbitrarily high values of diagnostic specificity and do not reflect the real life situation. In contrast, approach 2) will lead to inferior diagnostic specificities, because up to one-third of randomly selected subjects of the general population without a history of allergic symptoms might still have allergen-specific IgE antibodies to one or more common allergen sources. These cases of “silent allergic sensitizations” with a lack of clinical relevance will always lead to unsatisfactory values of diagnostic specificity for allergen-specific IgE antibody assays or for other “sensitization tests” (eg, skin prick test, basophil-based tests) as well.


diagnostic specificity

the probability (P) that the test is negative (T-), given that the subject being tested is disease free (D-), ie, P(T-|D-); or, the ability of a test under study to give a negative result for subjects not having the disease in question (MM01).


diagnostic specificity

the ability of a test to give a negative result for patients who do not have the disease or condition for which they are being tested

Project: M55

NOTE: It is measured as the ratio of negative tests to the total number of tests in those that do not have the disease or condition and is expressed as a percentage.


diagnostic specificity

the ability of a measurement procedure to give a negative result for subjects who do not havethe disease or condition for which they are being measured

Project: EP33

NOTE: In the context of EP33, diagnostic specificity refers to the ability of a delta check rule to correctly exclude patient specimens that do not have identification or integrity issues, and correctly exclude specimens from patients who do not have clinically important changes in their conditions.


diagnostic specificity

as used in ILA20, the ability of a test to correctly identify samples in which allergen-specific IgE antibody is absent; it correlates the absence of allergen-specific IgE antibody in the serum of patients who are defined by clinical criteria and/or gold standard laboratory tests as truly not allergic;

NOTE: Specificity for IgE antibody is ideally determined by testing a panel of serum samples from subjects with a negative history of allergic disease and evidence of the absence of IgE antibody positivity by an alternative accepted method such as skin testing, provocation testing, and/or an accepted reference serology method (provided its sensitivity and specificity are known). The serum panel should reflect patients from a variety of allergic disease states relevant to that allergen specificity as positive controls as well as healthy nonatopic negative controls.


diagnostic specificity

See clinical specificity.

Project: NBS05


diagnostic specificity

the proportion of subjects who do not have a specified clinical disorder (or condition of interest) whose test results are negative or within the defined decision limit;

Project: MM22, H60, MM23

NOTE: The term “diagnostic specificity” (Europe) is equivalent to “clinical specificity” (United States); NOTE 2: In laboratory testing, the ability of a test to give a negative result for patients who do not have the disease or condition for which they are being tested. It is measured as the ratio of negative tests to the total number of tests in those who do not have the disease or condition, and expressed as a percentage.


diagnostic specificity

the ability of a measurement procedure under study to give a negative result for subjects not having the disease/target condition in question;

Project: I/LA20, EP19

NOTE: Formerly, the term clinical specificity was used in CLSI documents.


diagnostic specificity

as used in this guideline, the ability of a test to correctly identify samples in which allergen-specific IgE antibody is absent; it correlates the absence of allergen-specific IgE antibody in the serum of patients who are defined by clinical criteria and/or designated reference laboratory tests as truly not allergic;

Project: ILA34

NOTE: Specificity for IgE antibody is ideally determined by testing a panel of serum samples from subjects with a negative history of allergic disease and evidence of the absence of IgE antibody positivity by an alternative accepted method such as skin testing, provocation testing, and/or an accepted reference serology method (provided its sensitivity and specificity are known). The serum panel should reflect patients from a variety of allergic disease states relevant to that allergen specificity as positive controls as well as healthy nonatopic negative controls.


diagnostic specimen

excreta, secreta, blood, and its components, tissue, tissue fluids, etc., that may contain an etiologic agent and is used for diagnosis.

Project: GP05


diagnostic specimen

see patient specimen.

Project: M29


diagnostic test

a measurement or examination of a diagnostic specimen for the purpose of diagnosis, prevention, or treatment of any disease or the assessment of health or impairment of health of an individual patient;

Project: ISO TR 15196, MM10, MM12, MM01, I/LA28, MM22

NOTE 1: Laboratory tests are often called in vitro diagnostic tests; NOTE 2: Diagnostic tests are generally performed to evaluate the genetic status of 1) symptomatic individuals, 2) those who are at increased risk for a particular disorder due to a positive family history, or 3) to confirm the findings of a prior screening test.


diagnostic test

See confirmatory test.

Project: NBS02


diagnostic test

a measurement or examination used to classify subjects into a particular class or clinical state;

Project: EP24

NOTE: Laboratory tests are often called “in vitro diagnostic” tests.


diagnostic test

See confirmatory test.

Project: NBS05


diagnostic testing

an additional test with very high specificity that may be performed, usually following another diagnostic test of lower specificity, in order to confirm or not confirm the original result;

Project: MM10

NOTE 1: The first line of diagnostic tests or "screening tests" are generally optimized for sensitivity and high throughput but may lack somewhat in specificity (i.e., they are prone to returning false-positive results); NOTE 2: Supplemental tests may be more labor-intensive and thus less suited for screening activity but should either have higher specificity or be based on detection of a different marker, such that the two tests in tandem will return very high sensitivity and specificity.


diagnostic testing

(confirmatory testing) 1) testing generally performed to evaluate the genetic status of individuals at increased risk for a particular disorder due to a positive family history or symptoms; 2) a test that confirms the presence or absence of a substance by another methodology or procedure that is either more sensitive, more specific, or both; 3) a clinical condition as a follow up to testing previously performed that indicated the patient being at higher risk for having a clinical condition.

Project: MM12


dial

fixed or moving part of a displaying device that carries the scale or scales (VIM93);

Project: VIM93

NOTE: In some displaying devices, the dial takes the form of drums or discs bearing numbers and moving relative to a fixed index or window. (VIM93)


dichotomous

acute angle branching into two equal branches.

Project: M54


dideoxynucleotides

(ddNTPs) nucleotides lacking a 3'-hydroxyl (-OH) group on their deoxyribose sugar (MM18).

Project: MM18


dielectric constant

the measure of a sample’s ability to obstruct the microwave energy as it passes through the medium; the loss (dielectric) factor measures the sample’s ability to dissipate that energy;

Project: GP28

NOTE: The term "loss" is used to indicate the amount of input microwave energy that is lost to the sample by being dissipated as heat in the sample.


diethylstilbestrol

(DES) synthetic, nonsteroidal estrogens administered during the last century to gravid women at risk for early pregnancy loss;

Project: GP15

NOTE: There is evidence that administration may have caused adenosis (non-neoplastic) and clear cell adenocarcinoma (neoplastic) in the female genital (cervix and vagina) tract of some of the daughters who were exposed in utero.


difference plot

a plot of the difference between a measured value and a reference concentration plotted on the y-axis vs the reference concentration on the x-axis;

Project: EP10, EP09

NOTE 1: Often, a dashed line is drawn at zero difference; NOTE 2: The reference concentration is often expressed as the average of the results of the measurements; NOTE 3: The difference may be expressed relative to the reference concentration.


different

in bacterial strain typing, the results for two isolates are described as "different" based on predefined criteria; this characterization implies that the isolates are not derived from a common (recent) ancestor (MM11);

Project: MM11

NOTE 1: The process for establishing such criteria is discussed in Section 9 of CLSI document MM11; NOTE 2: See also indistinguishable, similar.


differentiation assay

(HIV) an assay that distinguishes between HIV-1 and HIV-2 antibodies.

Project: M53


DiGeorge syndrome

(DGS) a clinical diagnosis referring primarily to a syndrome with a conotruncal heart defect, hypoparathyroidism, and aplasia or hypoplasia of the thymus gland. Variable additional findings have been noted (see 22q11.2 deletion syndrome);

Project: NBS06

NOTE 1: Not all patients with a clinical diagnosis of DGS will have a deletion of 22q11.2; NOTE 2: Patients with DGS may be described as having complete or partial DGS based on the severity of the thymic defect. “Partial” DGS comprises 99% of patients who have a normal or hypoplastic thymus. Approximately 1% of patients have “complete” DGS; absence of development of the thymus and an absence of T-cells in the peripheral blood resulting in a profound impairment of cellular immunity, similar to severe combined immunodeficiency (SCID). Newborns with complete DGS will likely be identified by the T-cell receptor excision circle (TREC) assays used for SCID newborn screening (NBS). They will require immune reconstitution (eg, thymic transplantation); NOTE 3: NBS programs have observed infants with partial DGS with low TREC levels at birth which increase over time, eventually reaching the normal range.


digital measuring instrument digital indicating instrument

measuring instrument that provides a digitized output or display (VIM93);

NOTE: This term relates to the form of presentation of the output or display, not to the principle of operation of the instrument.


digital signal processors

(DSP) electronic components of instruments that change or analyze in real time information that was digitized from analog signals.

Project: I/LA24


digital signature

a value computed with a cryptographic algorithm and appended to a data object in such a way that any recipient of the data can use the signature to verify the data’s origin and integrity. (RFC 2828)

Project: AUTO09


Digital Signature Algorithm

(DSA) an asymmetric cryptographic algorithm that produces a digital signature in the form of a pair of large numbers. The signature is computed using rules and parameters such that the identity of the signer and the integrity of the signed data can be verified. (See: Digital Signature Standard.) (RFC 2828)

Project: AUTO09


Digital Signature Standard

(DSS) the U.S. government standard that specifies the Digital Signature Algorithm (DSA), which involves asymmetric cryptography. (RFC 2828)

Project: AUTO09


diluent

the material used to make a concentrated material weaker;

Project: NRSCL08, H51

NOTE 1: The diluent is usually a liquid or a gas; NOTE 2: A liquid diluent may also be used to reconstitute a dried material to its original concentration (Cf. POL1/2).


dilution

the process of adding a material, usually a liquid or gas, to another material or substance for purposes of decreasing the concentration or activity of the former

Project: H48


dimension of a quantity

expression that represents a quantity of a system of quantities as the product of powers of factors that represent the base quantities of the system (VIM93); EXAMPLES a) in a system having base quantities length, mass and time, whose dimensions are denoted by L, M and T respectively, LMT-2 is the dimension of force; b) in the same system of quantities, ML-3 is the dimension of mass concentration as well as of mass density.

NOTE 1: The factors that represent the base quantities are called "dimensions" of these base quantities; NOTE 2: For details of the relevant algebra, see ISO 31-0.


dimorphic

having two morphological forms.

Project: M54


DIN

Deutsches Institut für Normung (German Standards Institute)


diode

a device that conducts electric current run in one direction only.

Project: GP28


dipolar molecules

molecules that are configured such that electrons favor one region of the molecule, resulting in an uneven spatial distribution of electrons and charge so that one side is slightly negatively charged relative to the somewhat more positively charged other side.

Project: GP28


dipole rotation

the net alignment, due to the electric field, of molecules in the sample that have permanent or induced dipole moments.

Project: GP28


direct analysis

measurement made directly on an undiluted specimen, e.g., whole blood, plasma, or sweat (Cf. C29).

Project: C29


direct antiglobulin technique

an analytical method in which the primary antibody, already bound to a particle (e.g., erythrocyte or bacterium), is detected by an agglutination of particles upon addition of an antiglobulin.


direct antiglobulin test

(DAT) a test in which AHG is used to determine whether RBC have been coated in vivo with IgG, complement, or both.

Project: ILA33


direct Coomb’s test

See direct antiglobulin technique.


direct cost

a cost that is identifiable directly with a particular activity, service, or product of the program experiencing the costs

Project: GP45


direct cost

an expense that can be traced directly to (or identified with) a specific cost center or cost object such as a department, process, or product; costs such as labor, reagents, or supplies that vary with the rate of output but are uniform for each unit of production and are usually under the control and responsibility of the department manager.

Project: QMS20


direct FTH measurement procedures

measurement procedures in which hormone is isolated from the protein-bound moiety prior to direct measurement of the amount sequestered (e.g., by immunoassay)

Project: C45


direct INR determination

INR determination from a PT/INR calibration line determined using certified plasmas without employing an ISI and MNPT (H54).

Project: H54, H47


direct lighting

light that is directed downward toward the work surface

Project: QMS04


direct reading photometer

a photometer with a measurement scale that has been calibrated directly in units of the analyte measured;

NOTE 1: If the analyte is hemoglobin, then the device might be termed a hemoglobinometer; NOTE 2: This should be contrasted with the special case spectrophotometer, which has the additional characteristic of being able to control the frequency and/or wavelength of the source light.


direct reading photometer

a photometer whose measurement scale has been calibrated directly in units of hemoglobin concentration;

Project: H15

NOTE 1: These units may be grams per liter (g/L), or millimoles per liter (mmol/L); NOTE 2: An alternative term sometimes used is "hemoglobinometer."


direct smear

(stool) approximately 2-mg suspension of feces in water or saline for the purpose of examination for parasites; primary aim is to see motility.

Project: M28


direct susceptibility test

a procedure based on inoculation of drug-containing media directly with a processed (concentrated after digestion and decontamination) specimen that is smear-positive for acid-fast bacilli (AFB) to determine the proportion or percentage of resistant MTBC in the patient’s bacterial population.

Project: M24


direct thrombin inhibitor

a class of drugs (either oral or intravenous [IV]) that directly inhibit the enzyme thrombin (without the need for a cofactor) (H47).

Project: H47


direct track sampling

the process in which aspiration of a sample occurs directly from the specimen container while it is on the transportation system, whereby the instrument probe extends to reach the specimen container on the transportation system;

Project: AUTO02, AUTO07

NOTE: The integrity of this process requires reliable agreement between the transportation system and the instrument and specimen processing and handling devices regarding point of reference (POR) to guide movement of the probe to the specimen.


directional airflow

air supply and exhaust system that is laid out to guide the movement of air in a specific direction

Project: QMS04


directions for use

See instructions for use.


directions of the specimen

the orthogonal axes.

Project: AUTO02


director

the person designated as having primary responsibility for the point-of-care blood glucose testing service

Project: POCT, POCT17, POCT12


disaggregation

the process by which platelet aggregates become separated into single platelets, resulting in a reversible change in transmittance or impedance (CLSI document H58).

Project: H58


disaster

state of a community threat to life and property of unusual magnitude that exhausts or threatens to overwhelm local resources;

Project: GP36

NOTE 1: In GP36, it is assumed that the disaster is of great magnitude, likely to be associated with a large number of injured, contaminated, or dead; NOTE 2: It is synonymous with “incident” or “event.”


disaster mortuary operations team

(DMORT) a multidisciplinary forensic team which, with necessary support equipment, can be deployed to assist in the investigation of a mass fatalities incident;

NOTE 1: DMORT operates under the auspices of NDMS and can be activated under several legal authorities; NOTE 2: DMORT is accessed by the local medical examiner/coroner through a request to their EMA.


discrepant result

result that is inconsistent to a clinically significant degree, with another result obtained from the same specimen, with a result from another measurement procedure or with a well-substantiated clinical diagnosis;

Project: EP07, C56

NOTE: In C56, the "discrepant result//spurious result" would be a result inconsistent with another result obtained from the same sample in the absence of any clinically significant bias due to hemolysis, icterus, or lipemia/turbidity interference.


discrimination

(threshold) largest change in a stimulus that produces no detectable change in the response of a measuring instrument, the change in the stimulus taking place slowly and monotonically (VIM93);

NOTE: The discrimination threshold may depend on, for example, noise (internal or external) or friction. It may also depend on the value of the stimulus.


discrimination threshold

largest change in a value of a quantity being measured that causes no detectable change in the corresponding indication (JCGM 200:2008);

Project: ISO IEC Guide 99

NOTE: Discrimination threshold may depend on, eg, noise (internal or external) or friction. It can also depend on the value of the quantity being measured and how the change is applied (JCGM 200:2012).


discriminatory power

in bacterial strain typing, the probability that two random, epidemiologically unrelated isolates will be distinguished by the typing method (ie, identified as different strain types) (MM11);

Project: MM11

NOTE: Ideally, each unrelated isolate is detected as unique, but, in practice, some are indistinguishable (MM11).


disinfectant

agent capable of causing disinfection (ISO 15190)

Project: ISO 15190


disinfectant

agent capable of disinfecting inanimate surfaces (eg, work surfaces or medical devices) (modified from ISO 15190)

Project: M29, POCT13

NOTE 1: Most disinfectants are not effective sterilizers; NOTE 2: See disinfection.


disinfectant

a substance used to reduce the concentration of bacteria, fungi, or viruses on a surface.

Project: M47


disinfection

process to reduce the number of microorganisms, but not usually of bacterial spores, without necessarily killing or removing all organisms (ISO 15190)

Project: ISO 15190


disinfection

a procedure that kills pathogenic microorganisms but not necessarily their spores;

Project: GP05

NOTE: Chemical germicides formulated as disinfectants are used on inanimate surfaces (eg, medical devices); they should not be used on skin or body tissues.


disinfection

process to eliminate most pathogenic microorganisms without necessarily killing or removing all organisms (eg, bacterial spores) (modified from ISO 15190)

Project: M29, POCT13

NOTE 1: A process that reduces or completely eliminates all pathogenic microorganisms, except spores; NOTE 2: Chemical germicides that are formulated as disinfectants are used on inanimate surfaces (medical devices, etc.) and should not be used on skin or tissues; NOTE 3: See disinfectant.


disk

in microbiological testing, a filter paper wafer containing a defined concentration of an antimicrobial agent for use in a disk-agar diffusion antimicrobial susceptibility test (Cf. M2, M23, M31, M37).

Project: VET03


displaying device indicating device

part of a measuring instrument that displays an indication (VIM93);

NOTE 1: This term may include the device by which the value supplied by a material measure is displayed or set; NOTE 2: An analogue displaying device provides an analogue display; a digital displaying device provides a digital display; NOTE 3: A form of presentation of the display either by means of a digital display in which the least significant digit moves continuously, thus permitting interpolation, or by means of a digital display supplemented by a scale and index, is called a semidigital display; NOTE 4: The English term readout device is used as a general descriptor of the means whereby the response of a measuring instrument is made available.


displaying instrument indicating (measuring) instrument

measuring instrument that displays an indication (VIM93); EXAMPLES: a) analogue indicating voltmeter; b) digital frequency meter; c) micrometer;

Project: VIM93

NOTE 1: The display may be analogue (continuous or discontinuous) or digital; NOTE 2: Values of more than one quantity may be displayed simultaneously; NOTE 3: A displaying measuring instrument may also provide a record.


displaying measuring instrument

indicating measuring instrument where the output signal is presented in visual form (JCGM 200:2012).

Project: ISO IEC Guide 99


disposal

act of indefinitely sequestering either treated or untreated waste, such as by burial in a landfill or waste pile;

Project: GP05

NOTE: Indiscriminate release to the environment is also considered disposal.


disruption

complete breakage of cell walls and plasma membranes of solid tissues and cells, which is absolutely necessary to release all the DNA and RNA contained in the specimen and to release and inactivate endogenous nucleases;

Project: MM13

NOTE 1: Different specimen types (e.g., tumor tissues vs. PBMCs) require different methods to achieve complete disruption; NOTE 2: Incomplete disruption results in significantly reduced nucleic acid yields.


distal

remote; farther from the point of reference (Dorland's Illustrated Medical Dictionary. 32nd ed. Elsevier Saunders; 2012); EXAMPLE: The wrist is distal to the elbow.

Project: GP41


distal deep vein thrombosis

refers to intravenous thrombosis in a lower extremity affecting the veins distal to the popliteal fossa.

Project: H59


distillation

a purification process that utilizes changing the phase of a substance from liquid to vapor and back to liquid, usually at the boiling temperature of the substance, in order to separate it from other substances with higher or lower boiling points

Project: GP40


distribution

the frequency of occurrence of an item or value in each segment of categories over a range of categories;

Project: NRSCL08

NOTE: For data or relationships involving the two variables, frequency and value, the pattern of data is graphically plotted as a function of the values (x-axis) versus the frequency that value is obtained (y-axis).


distribution-free

(statistical procedure) one that does not presuppose that the data arise from a distribution of a particular kind, such as the normal (gaussian) family of distributions;

Project: EP24

NOTE 1: A near-synonym is “nonparametric”; NOTE 2: For example, drawing a histogram is a simple distribution-free operation, as is any “local” maneuver aimed at smoothing the histogram or smoothing a trend. Any procedure exclusively based on an ordering (ranking) of observations, rather than on their numerical values, is also distribution-free; NOTE 3: “Distribution-free” does not mean “assumption-free.” Assumptions of representative (fair) sampling and independence (independent observations), for instance, are universal.


distributor

person or legal entity that furthers the marketing and/or selling of a device from the original place of manufacture to the ultimate user without modifying the device, its packaging, or its labelling (ISO 18113)

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3, M50

NOTE: Adapted from US Code of Federal Regulations (CFR), Title 21, Part 803 — Medical Device Reporting Regulation], 803.3 (g) (ISO 18113-1).


DNA amplification failure

as used in NBS06, the failure to identify T-cell receptor excision circles or a reference gene sequence due to inadequate amplification of the selected DNA segment(s).

Project: NBS06


DOA

drugs of abuse

Project: C52


docking site

1) the location of the physical interface between two components of a system; 2) in Automation, the interface between the transportation system and the instrument and/or the specimen processing and handling devices where the specimen container arrives for sampling to occur.

Project: AUTO01, AUTO02


docking station

equipment designed to physically connect and interface a POCT device, including all of the wiring, cables, ports, connections, power supply, and communication formats and protocols (CLSI document POCT02).

Project: POCT02


Docking Station

a mechanical and electrical interface that supports the use of a POC Device, typically employing legacy mechanical interfaces, connectors, protocols, and power delivery methods

Project: POCT01


document

(noun) any recorded item of a factual or informative nature, either paper or electronic; written or electronically generated information and work instructions;

Project: ILA33

NOTE: Examples of documents include quality manuals, procedures, or forms.


document

(n) information and the medium on which it is contained (ISO 9000)

Project: QMS16, QMS21, QMS25, ISO 9000, QMS14, QMS06, GP26, QMS02, QMS15

NOTE: Documents may be paper-based or electronic.


document

any written item of a factual or informative nature.


document

(verb) to capture information for use in documents through writing or electronic media.

Project: ILA33


document control coordinator

person responsible for managing document creation, review, editing, and distribution.

Project: QMS02


dominant

describes a trait or disorder in which the phenotype is expressed in those who have inherited only one copy of a particular gene mutation.

Project: MM19


donor specimen

a urine specimen collected from a subject for the purpose of forensic testing

Project: C52

NOTE: The term "e;donor"e; is used in contrast to "e;patient"e; to distinguish forensic from clinical testing.


donor surrogate

a cell that has the same mismatched antigens that occurred with the donor.

Project: ILA29


donor-specific antibody

(DSA) antibody formed in the recipient that is directed against the mismatched HLA antigens found in the donor.

Project: ILA29


dose-response curve

a graphical representation of the relationship between the amount (dose) of a pharmacologically active agent administered to organisms and either the number or percentage of organisms that show a response.

Project: NRSCL08


dot plot

two-dimensional representation of flow data; each dot represents an individual cell or event;

Project: ILA29

NOTE: A scatter plot shows forward scatter (cell size) on the x-axis and side scatter (cell internal complexity) on the y-axis. A fluorescence dot plot shows one color on the x-axis (eg, fluorescein isothiocyanate [FITC]) and another color (eg, phycoerythrin) on the y-axis, with each color linked to a cell marker of interest. Fluorescence dot plots are divided into four quadrants: double negative cells or events, double positive, single positive along x-axis, and single positive along y-axis.


double-voided specimen

a urine specimen that is collected together with a blood specimen (within n minutes) to compare the concentration of an analyte (e.g., glucose) in these body fluids at that time (Cf. GP8).

Project: GP08


downdraft

movement of air through exhaust vents located near the floor to take airborne particulates or chemical fumes that are heavier than air out of a space

Project: QMS04


download

data transmitted from an information system to a clinical instrument

Project: LIS02


draft

a rough or preliminary piece of writing.

Project: QMS02


drainage fluid

fluid that drains through the skin from a surgical site, wound, or other penetrating injury;

Project: C49

NOTE 1: The medical need is typically to determine whether the fluid is produced locally at the cutaneous site or whether it derives from deeper organ injury (e.g., kindey and urinary tract, liver and gall bladder, pancreas, intestine, stomach, esophagus, etc.); NOTE 2: Quantitation of organ-specific analytes in a drainage fluid can often provide unique diagnostic information to indicate what organs might need surgical repair.


draw

quantity of blood drawn into the venous blood collection tube from a venipuncture

Project: GP39, GP34

NOTE: For testing purposes, the conditions are defined as follows: 101 kPa (760 mm Hg) pressure and 20 °C ambient temperature. The temperature of the blood collected is assumed to be 37 °C.


dried blood spot

(DBS) a specimen collected for laboratory testing using an approved medical device comprising a specified filter paper on which printed circles indicate the area to be filled with whole blood, and air-dried for transport or storage

Project: NBS07, NBS04

NOTE 1:  Specimens collected using an approved medical device should yield a reproducible volume of blood per spot (typically 75 to 100 mL for a 12.5-mm circle, 35 to 50 mL for a 10-mm circle); NOTE 2: In newborn screening, the DBS is ideally collected directly from a heelstick using no anticoagulants because anticoagulants, particularly heparin and EDTA, have been shown to interfere with certain assays.


dried blood spot

(DBS) a cellulose-based medium onto which drops of blood have been applied and dried

Project: C50

NOTE: The cellulose is manufactured in such a manner that the volume of blood applied meets a specific standard.


dried blood spot

(DBS) a specimen collected for laboratory testing using an approved medical device (eg, by the US Food and Drug Administration) comprising a specified filter paper on which printed circles indicate the area to be filled with whole blood. Typically, a specimen of approximately 75 µL of whole blood is applied to a 12–13 mm diameter spot printed on the filter paper and air-dried for transport or storage;

Project: NBS06

NOTE: In newborn screening, the DBS is ideally collected directly from a heelstick using no anticoagulants. Anticoagulants, particularly heparin and EDTA, have been shown to interfere with certain assays.


dried blood spot

(DBS) blood collected from a heel stick and air dried on an approved filter paper matrix

Project: NBS03, NBS05


drift

a slow, {systematic}change of a metrological characteristic of a measuring instrument {or system, from the start to completion of a set of replicate measurements}(VIM93-5.16).


drift

characteristic slow change of a metrological of a measuring instrument (VIM93)


drift

(sensor) a progressive and gradual change in deviation between sensor reading and reference value over time (POCT05).

Project: POCT05


drill

see exercise.

Project: GP36


droplet nuclei

the small residues that result from evaporation of fluid from droplets emitted by an infectious host, or created by an atomizing device, or accidentally in microbiology laboratories, autopsy rooms, etc;

Project: M29

NOTE: Droplet nuclei are generally less than or equal to 5 µm in size and can remain suspended in air for extended periods of time.


droplet precautions

applies to patients with known or suspected to have serious illnesses transmitted by large particle droplets (greater than 5 µm in size).


droplets

particles of moisture produced by aerosolization that may carry an infectious agent;

Project: M29

NOTE 1: Droplets larger than 150 µm generally fall to a surface; NOTE 2: Droplets smaller than 150 µm generally evaporate and may remain suspended in air.


drug

any substance that, when absorbed into a living organism, may modify one or more of its functions.

Project: C43


drug

a substance used to treat an illness, relieve a symptom, or modify a chemical process in the body for a specific purpose.

Project: ILA34


drug effect

term commonly used to describe the physiological influence of a drug on the in vivo concentration of a substance, as opposed to an in vitro effect on the analytical process.

Project: EP07


drug of abuse

drug used for a nontherapeutic purpose.

Project: C43


dry chemistry analysis

analysis that uses a test strip or reaction cartridge with no liquid reagent requirement and no liquid waste.

Project: POCT07


dual-parameter display

a graphical representation of data in which correlated values for two different parameters measured on the same cell are plotted on an x,y grid.

Project: H43, H42, H52

NOTE: This representation of data may also be known as dot plot, contour plot, cytogram, or two-parameter histogram.


dual-platform method

a method for the determination of absolute cell concentration using data derived both from flow cytometric measurements and a second instrument, generally a hematology analyzer (H42, H43);

Project: H43, H42

NOTE: The flow cytometer is used to obtain the fraction of the cellular subpopulation of interest present within a more abundant parent cell population, usually either total lymphocytes or total WBC. The absolute concentration of the parent population is provided by an independent assay of the sample on a second instrument. The product of these two measurements gives the absolute concentration of the population of interest. The disadvantage of the method is a compounding of the error inherent in each of the two measurements, and for this reason is judged inferior to single-platform methodologies (H42, H43).


Duchenne/Becker muscular dystrophy

a severe progressive form of muscular dystrophy (progressive wasting of muscles) of males that appears in early childhood and affects the muscles of the legs before those of the arms and the proximal muscles of the limbs before the distal ones; inherited as an X-linked recessive trait and characterized by complete absence of the protein dystrophin (MM17).

Project: MM17


ducts

metal pipes for the distribution of air

Project: QMS04


duodenum

the proximal portion of the small intestine (Strongyloides stercoralis, Giardia lamblia);

Project: M28

NOTE: Although some individuals have changed the species designation for the genus Giardia to G. intestinalis or G. duodenalis, there is no general agreement. Therefore, for this listing, we will retain the name Giardia lamblia.


duplicate read

in massively parallel sequencing, independent reads that are identical in nature and typically removed to avoid biasing determination of allele frequencies;

Project: MM09

NOTE: In metagenomics, typically refers to identical or nearly identical sequences that, because of artifacts in the sequencing process, appear present in numbers greatly exceeding the expectations based on chance and can produce an overestimation of relative presence of taxa, genes, and function.


duplication

the execution of a treatment more than once under similar conditions (ISO 3534-3-1.11);

Project: ISO 3534

NOTE 1: Duplication, as contrasted with replication, refers to a single element of an experiment; NOTE 2: Duplication usually involves a fresh experimental unit, such as a new sample or, when a single unit is involved, an independent retesting of the levels of the factors being studied on that unit (ISO 3534-3-1.11).


duplication

amplification of any region of DNA;

Project: MM19

NOTE: If an entire gene is duplicated, the second copy of the gene is often free from selective pressure, ie, mutations within may have no deleterious effects to its host organism. Thus, the duplicated gene accumulates mutations faster than a functional single-copy gene, over generations of organisms.


duty cycle

(magnetron cycling) Microwave power can be applied continuously but is usually pulsed. The power output of the magnetron is controlled by “cycling” the magnetron on and off at full power for some fraction of time to obtain an average power level. The duty cycle of a magnetron is the time the magnetron is ‘on’ divided by the total time of the cycling period;

Project: GP28

NOTE: Domestic microwave devices have relatively long cycling periods based on intervals of 1/6 min. (10 seconds) and longer, as compared to laboratory analytical grade microwave equipment, which has cycling periods of 1/60 min. (1 second), making heat control more difficult in household microwave devices.


duty cycle

proportion of time during which a device or system is usefully operated. For mass spectrometry, the part of ions of a particular m/z over which the mass analyzer can measure ions. It is expressed in Th, or in µ for an ion carrying an elementary charge, ie, z = 1.

Project: C62


dwell time

the amount of time a mass analyzer monitors ions of a particular m/z

Project: NBS04


dwell time

the amount of time the mass spectrometer is focused on and attracting ions of a particular mass

Project: C50


dye

colored organic compound that, when dissolved in a suitable solvent, can impart colour to a material (ISO 19001)

Project: ISO 19001

NOTE: The physical origin of colour is the selective absorbance (and/or emission) in the visible region of the electromagnetic spectrum between 400 nm and 800 nm. Dyes are molecules with large systems of delocalized electrons (conjugated p electronic system). The light absorbance characteristics of dyes are displayed by absorbance spectra, resulting from plotting absorbance of light against wavelength. The shape of the spectra and the wavelength at maximum absorbance depend on the chemical structure of the dye, the solvent, and on the conditions of the spectral measurements.


dye intercalation

the reversible inclusion of a dye between the molecules of either DNA or RNA;

Project: MM19

NOTE: These dyes, eg, ethidium bromide, may be used to visualize nucleic acid on an electrophoretic gel.


dynamic range

the total span over which an analysis can provide results;

Project: I/LA18, I/LA23, VET03, MM19

NOTE 1: Analytically, the functional range of an assay over which concentrations of an analyte can be measured with accuracy and precision; NOTE 2: Physiologically, the full range of analyte levels to be expected in patient samples (Cf. I/LA18).


dysHb

See dyshemoglobin.

Project: POCT11


dyshemoglobin

a hemoglobin form that is not functionally capable of reversible physicochemical association with oxygen;

Project: POCT11

NOTE: The known dyshemoglobins affecting pulse oximetry are carboxyhemoglobin (COHb), methemoglobin (MetHb), and sulfhemoglobin (SulfHb).


dysplasia

precancerous cellular changes in the cervix that include a spectrum of cellular abnormalities, described as mild, moderate, and severe or marked dysplasia;

Project: GP15

NOTE: Dysplasia terminology has been replaced with Bethesda terminology for Pap tests; however, it is still used for histologic specimens in many laboratories.


D-zone test

a disk diffusion test using clindamycin and erythromycin disks placed in close proximity to detect the presence of inducible clindamycin resistance in staphylococci and streptococci.

Project: M07, M02


EBV transformed cell lines

infection of cells with Epstein Barr virus and subsequent integration of viral DNA into the host genome, resulting in continued expression of viral genes and transformation of the cells;

Project: ILA29

NOTE: Phenotypic consequences of virally transformed cells include high saturation density, anchorage independent growth, loss of contact inhibition and oriented growth, cytoskeletal disruption, and immortalization.


echogenic bowel

bowel that is a brighter signal than liver when identified on fetal ultrasound, which is associated with an increased risk of cystic fibrosis

Project: NBS05


eclipse period

the interval between infection with HIV and first detection of viral nucleic acid in plasma using a nucleic acid test with a low detection limit.

Project: M53


ectoparasite

a parasite living on the exterior of another being;

Project: POCT10

NOTE: Examples include lice, scabies, chiggers, and dermatophytes.


education

the act or process of imparting or acquiring knowledge, developing the powers of reasoning and judgment, and generally preparing oneself or others intellectually

Project: QMS16


effective F/P ratio

the fluorescence yield of a fluorochrome-ligand conjugate (FLC) expressed as moles of equivalent soluble fluorochrome per mole of FLC (in solutions), or as molecules of equivalent soluble fluorochrome (MESF) per molecule of FLC (on stained particles);

Project: I/LA24

NOTE 1: The word "ratio" is optional since it is implied by the term "F/P"; NOTE 2: The term "F/P" originally meant "fluorochrome to protein" ratio when it was applied to molar quantities of fluorochrome conjugated to the carrier protein. Since most ligands used in QFC are proteins, the term has been retained. However, FLC reagents often contain an excess of carrier protein for stability, and carrier protein should not be included in determining either molar or effective F/P ratios. For that reason, "F/P" is sometimes taken to mean "fluorochrome to probe" ratio, where the term "probe" implies an active species such as the ligand of a receptor, whether or not it is protein.


effectiveness

extent to which planned activities are realized and planned results are achieved (ISO 9000)

Project: QMS06, ISO 9000, GP26, QMS14, QMS15, QMS20


efficacy

(effectiveness) extent to which planned activities are realized and planned results are achieved (ISO 9000)

Project: GP35


efficacy

the ability of a medical device to achieve the expected result in attaining diagnosis or treatment, such as the ability of a cardiac defibrillator to revert fibrillation (ISO Guide 63- 2.4).


efficiency

the degree to which a system or component performs its designated functions with minimum consumption of resources.

Project: AUTO08, GP35


efficiency

(of immunoassays) the percentage (number fraction multiplied by 100) of results that are true results, whether positive or negative.

Project: ILA18, ILA23, H20


efficiency

a statistical parameter that defines the percentage (number fraction multiplied by 100) of results that are true results as measured by an analytical method.

Project: I/LA20


efficiency

relationship between the result achieved and the resources used (ISO 9000)

Project: QMS06, GP26, QMS14, QMS15, QMS20


effluent

outflow or discharge of liquid waste, as from a sewage system, factory, or nuclear plant.

Project: GP17


electrodeionization

(EDI) technology combining ion-exchange resins and ion-selective membranes with direct current to remove ionic impurities from water and maintain the resin in regenerated condition

Project: GP40


electrometer

a device that conditions (i.e., amplifies) a signal from a sensor and prepares it for collection and processing.

Project: C39


electron ionization

ionization of an atom or molecule by electrons that are typically accelerated to energies between 10 and 150 electron volts (eV) in order to remove one or more electrons from the molecule (IUPAC 2006);

Project: C43, C50

NOTE 1: Electrons and photons do not affect molecules or atoms. They interact with them in ways that result in various electronic excitations including ionization. For that reason, it is recommended that the terms "electron impact" and "photon impact" be avoided; NOTE 2: This term should be used instead of electron impact, because electrons and photons do not “impact” molecules or atoms, but interact with them in ways that result in various electronic excitations, including ionization (C50).


electronic control

control procedure or algorithm that checks the electronics, software, or other components or procedures of a diagnostic measuring system via electronic circuits or software logic.

Project: EP23


electronic data interchange

(EDI) the interface protocols and message formats required to exchange data between information systems or computers (CLSI document POCT02);

Project: POCT02

NOTE 1: The acronym is general (applying to all such exchange protocols and languages); however, in some industries it has come to refer to specific implementations (CLSI document POCT02); NOTE 2: In the point-of-care domain, this term is occasionally used to refer to the specific interface found among point-of-care data management systems, laboratory information systems, clinical information systems, and other systems that serve as the final repository of POC results (CLSI document POCT02).


Electronic Data Interchange

(EDI) a term used in many industries to describe protocols to exchange data between enterprise-class information systems;

Project: POCT01

NOTE 1: The acronym is general (applying to all such exchange protocols and languages); however, in some industries it has come to refer to specific implementations; NOTE 2: In the point-of-care domain, this term is occasionally used to refer to the specific interface found between point-of-care data management systems, laboratory information systems, clinical information systems, and other systems that serve as the final repository of POC results.


electronic medical record

(EMR) a computerized patient medical history (POCT02);

Project: POCT02, POCT07

NOTE: Hospitals are converting older paper copies of records with handwritten physician and nursing notes to computerized records that can store and transfer data in a standardized fashion (POCT02).


electropherogram

the visualization of a sequence ladder characterizing the signal strength, noise, base spacing, and base calls as seen by the sequencing software;

Project: MM09

NOTE: This chart can be used as a tool to evaluate the quality and accuracy of the sequence.


electropherogram

a representation of that which is created during electrophoresis;

Project: MM10

NOTE: In the process of running a sequencing gel, the profile of the different colored fluorescent dyes, which is seen by the laser as the various oligonucleotides pass by, is interpreted by sequencing analysis software and an electropherogram of colored peaks is created.


electropherogram

the visualization of DNA sequence as a plot of fluorescence units over time characterizing the signal strength, noise, base spacing, and base calls generated by the sequencing software (MM18);

Project: MM18

NOTE: The data are a series of colored peaks where each peak represents one of the four different DNA bases (MM18).


electrophoresis

a method of separating large molecules (such as DNA fragments or proteins) from a mixture of similar molecules under the influence of an electric current (MM18);

Project: MM18

NOTE: Each kind of molecule travels through the medium at a different rate, depending on its electrical charge and size (MM18).


electrophoresis

see gel electrophoresis and capillary electrophoresis.

Project: MM09


electrophoresis

a laboratory technique used to separate mixtures of ionic solutes by the differences in the rates of migration in an applied electric field.

Project: NRSCL8, MM10, MM17


electrospray ionization

(ESI) an ionization technique that allows for the mass spectrometric analysis of labile and/or polar compounds

Project: NBS04

NOTE 1: The solution to be analyzed is sprayed through a capillary into a strong electric field creating fine droplets that evaporate (heated nitrogen drying gas assists the desolvation process), causing gas phase ions to be formed; NOTE 2: Because electrospray is a soft ionization technique, it produces little fragmentation of analyte molecules.


electrostatic (energy) analyzer

a device consisting of conducting parallel plates, concentric cylinders, or concentric spheres that separates charged particles according to their ratio of translational energy to charge by means of a voltage difference applied between the pair (IUPAC 2006).

Project: C43


electrostatic analyzer

an energy-focusing device for producing an electrostatic field perpendicular to the direction of ion travel (C50);

Project: C50

NOTE 1: Usually used in combination with a magnetic analyzer for double-focusing mass analysis; NOTE 2: The effect is to bring to a common focus all ions of a given kinetic energy (or more specifically, energy/charge) (C50).


elevations

graphic illustration of the vertical elements of a design, including casework and millwork

Project: QMS04


eligible population

the subset of the target population identified by an investigator who may be invited to participate in a prospective observational or experimental study design, or whose medical records will be identified by the investigator for review in a retrospective observational study design

Project: GP45

NOTE 1: The eligible population should be representative of the target population about which the investigator intends to make valid inferences about the truth of the study hypotheses; NOTE 2: Persons in the target population may not be eligible for a study because of ethical considerations of the risks in relation to benefits of participation in the study, study design issues related to efficiency, such as restricting the study to persons with more severe disease who are more likely to respond to interventions, or less likely to be lost to follow-up; NOTE 3: Inferences about the target population made from the study findings in the eligible and enrolled population are suspect if the eligible and enrolled populations differ from the target population.


ELISA

an abbreviation for enzyme-linked immunosorbent assay, a ligand binding assay in which a binding molecule (often an antibody or antigen) is attached to a solid-phase surface such as a microtiter plate well, and the extent of binding is determined by the enzymatic activity of an enzyme-conjugated ligand bound to the solid-phase surface from the solution phase;

Project: I/LA02, ILA29

NOTE 1: ELISA has become a term used generally to refer to solid-phase immunoassays, especially those conducted in microtiter plates, even if the label on the conjugate is not an enzyme; NOTE 2: Other platforms used for solid-phase ligand-binding assays include microbeads, sometimes called "suspension arrays," and slide-based protein microarrays.


emergency management agency

agency responsible for coordinating response to any type of emergency within its jurisdiction; county, state, or national.

Project: GP36


emergency operations center

community, county, or state command center which, when activated, centralizes and protects leadership responsible for coordinating a disaster response.

Project: GP36


emergency operations plan

facility, community, county, state, or national plan describing preparedness plans;

Project: GP36

NOTE: The community plan is often referred to as local emergency operations plan.


emergency power

back-up power system used in case of a public system outage

Project: QMS04


emergency shower

see flood shower


emission spectrum

the representation of the variation in the intensity of emitted radiation as a function of the wavelength or frequency of the emitted radiation.


empirical therapy

treatment initiated before determining the diagnosis of infection in a patient and/or before a specific etiological agent is identified and/or characterized as related to an infectious disease.

Project: M39


employee

an individual who agrees to work for an individual or entity (employer), is hired by the employer, fulfills the job requirements, works the specific job and hours, and is paid for the performance of the job completed for the employer

Project: QMS16

NOTE: An employee is a member of the personnel of the organization.


employer

a person or entity that hires an individual to work for that person or entity for an agreed upon salary, which may be either hourly or a fixed salary for a specific period of working time

Project: QMS16


empyema fluid

the presence of pus in a body cavity; usually refers to pus in the pleural cavity.

Project: H56


emulsion polymerase chain reaction

a type of polymerase chain reaction amplification in which single DNA molecules are isolated and amplified within individual water in oil micelles.

Project: MM09


en

a printer’s term. An “en” is one-half the width of an “em.” Readers desiring more detailed information are referred to Wikipedia or a typesetting manual.

Project: AUTO12


Encapsulating Security Payload

(ESP) an Internet IPsec protocol designed to provide a mix of security services—especially data confidentiality service—in the Internet Protocol. (RFC 2828)

Project: AUTO09


encoding

1) a system of assigning numeric values to characters; 2) a means of producing a unique combination of bits (a code) in response to an analog signal (IEEE-1007).

Project: AUTO01, AUTO02, AUTO03


encryption

cryptographic transformation of data (called “plaintext”) into a form (called “ciphertext”) that conceals the data’s original meaning to prevent it from being known or used. If the transformation is reversible, the corresponding reversal process is called “decryption,” which is a transformation that restores encrypted data to its original state. (RFC 2828)

Project: AUTO09


end user

personnel in the health care facility familiar with the medical device and its operation (H57).

Project: H57


endemic

restricted to a particular geographic region.

Project: M54


endogenous control

endogenous controls are used in gene expression studies to normalize gene expression values in the total RNA relative to expression levels of genes whose expression levels are invariant in a given tissue or tissues;

Project: MM16

NOTE: Endogenous controls are not within the scope of this guideline.


endogenous interferent

physiologically occurring substance in a sample (e.g., bilirubin or hemoglobin) that causes interference with the analysis of another substance.

Project: EP07


endoscopy

procedure in which an instrument is used for examination of the interior of a canal or hollow organ (GP20).

Project: GP20, MM17


endospore

a spore produced within a spherule.

Project: M54


endotoxin

a thermostable lipopolysaccharide component from the cell wall of viable or nonviable gram-negative microorganisms

Project: GP40


end-point immunoassay

an immunoassay where the signal is measured when the antigen antibody reaction has reached effective equilibrium and when any nonspecific component of the signal is assumed to be small and constant


end-point polymerase chain reaction

see polymerase chain reaction.

Project: NBS06


engineering controls

controls that isolate, minimize, or remove the blood-borne pathogens hazard from the workplace;

Project: X03

NOTE: That is, safer medical devices, such as sharps with engineered sharps injury protection and needleless systems as well as other medical devices designed to reduce the risk of percutaneous exposure to blood-borne pathogens. Examples include blunt suture needles and plastic or mylar-wrapped glass capillary tubes, as well as controls that are not medical devices, such as sharps disposal containers and biosafety cabinets.


engineering controls

facilities, equipment, or processes designed to isolate, enclose, or remove the hazard in order to prevent exposure in the workplace; EXAMPLES: Heating, ventilation, and air conditioning systems with directional airflow; biological safety cabinets; centrifuge safety cups; sharps disposal containers; self-sheathing needles; safer medical devices such as sharps with engineered sharps injury protections and needleless systems.

Project: M29


enhancement

the use of a reagent that nonspecifically increases signal in an assay (e.g., the use of polyethylene glycol to increase the rate of formation of antigen-antibody complexes) (Cf. I/LA18).

Project: I/LA18


ENQ

ASCII character denoting the word “enquiry,” which requests establishment of the communication phase;

Project: AUTO01, AUTO02, AUTO03

NOTE: Part of the protocols in CLSI documents LIS01 and LIS02.


enrichment

(nucleic acid or cellular) to increase in content or abundance, eg, to increase the abundance of one measurand within a complex mixture of nucleic acids or cellular components by the selective removal of other nonmeasurand nucleic acids or cell components.

Project: MM09


enrichment

(nucleic acid or cellular) to increase in content or abundance, e.g., to increase the abundance of one analyte within a complex mixture of nucleic acids or cellular components by the selective removal of other nonanalyte nucleic acids or cell components.

Project: MM13


enrolled population

1) the subset of the eligible and target population who are contacted, invited to participate, and actually give informed consent for participation in the study; 2) the subset of the eligible and target population whose medical records are actually reviewed and from which information is actually obtained and included in the study

Project: GP45

NOTE 1: The enrolled population is the achieved sample size; NOTE 2: Inferences about the target population made from the study findings in the eligible and enrolled population are subject to bias if the eligible and enrolled populations differ from the target population.


enterprise master patient index

a cross-reference of patient information that is kept current by rules to identify, match, and update data from multiple source applications (HealthIT2.com)

Project: GP49


entity

that which can be individually described and considered. (ISO 3534-1/93-2.1).

Project: ISO 3534


entropy

(thermodynamics) a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work

Project: GP28


environmental factors

conditions that may affect the analysis that include, but are not limited to, temperature, airflow, humidity, barometric pressure, light, power supply, vibration, electromagnetic radiation, and water.

Project: EP23


environmental factors

conditions that may affect the analysis that include, but are not limited to, temperature, airflow, humidity, vibration, and altitude.

Project: POCT07


environmental factors

variables that might affect the performance or efficacy of IVD reagents (eg, temperature, airflow, humidity, light).

Project: EP25


enzyme

any of various proteins… originating from living cells and capable of producing certain chemical changes in organic substances by catalytic action (RHUD1.7CD).


enzyme

substance that acts as a catalyst in living organisms, regulating the rate at which chemical reactions proceed without itself being altered in the process.

Project: NBS07

NOTE: See acid α-glucosidase.


enzyme activation

a process by which an increase in enzyme activity is brought about by the addition of coenzymes (organic compounds serving as cosubstrates) or activators (inorganic ions, such as Mg++ or K+) (SDELMT84).


enzyme activity

that function of an enzyme that is assayed by measuring conversion of substrate to product per unit time;

NOTE 1: Activity can be related to the rate of loss of substrate or rate of appearance of product; NOTE 2: Activity is a measure of the amount of an enzyme in terms of the one property that differentiates it from all other proteins, its specific catalytic activity (SDELMT84).


enzyme conjugate

one of the reagents of an immunoassay that has an antigen, analyte, or antibody complexed to an enzyme by a covalent linkage (Cf. I/LA18 ).

Project: I/LA18, I/LA28


enzyme immunoassay

(EIA) an immunoassay that uses the catalyzing properties of an enzyme for the detection of an immunological reaction.

Project: M53


enzyme inhibition

a decrease in enzyme activity;

Project: DI01

NOTE: This may result from temperature change, substrate depletion, end-product formation, or other causes (Cf. DI1).


enzyme system

an enzyme (or enzymes) and the necessary substrates and cofactors for an enzyme reaction. (Cf. DI1)

Project: DI01


enzyme-linked immunosorbent assay

(ELISA) a heterogeneous (requires separation of bound and free) immunoassay in which an analyte is captured by its corresponding antigen or antibody, then detected by an enzyme-conjugated reactant.

Project: I/LA18, POL1/2, H51


enzyme-linked immunosorbent assay

(ELISA) a ligand binding assay in which a binding molecule (often an antibody or antigen) is attached to a solid-phase surface, commonly a microtiter plate well. The antigen containing fluid is added to the antibody/antigen reaction. The extent of binding is determined by the activity of an enzyme that is conjugated with secondary antibodies that are added to the reaction along with the appropriate substrate. Color or light is used to measure the amount of product.

Project: H59


enzyme-linked immunosorbent assay

(ELISA) See enzyme immunoassay.

Project: M53


enzyme-linked immunospot

(ELISPOT) a laboratory technique in which the secreted products of a cell are specifically and locally captured on the surface of a filter plate and then detected by an enzyme-conjugated detection cascade, and soluble substrates that give colored, insoluble products;

Project: I/LA26

NOTE: Originally developed to detect specific antibody-secreting cells, the ELISPOT has been adapted to detect secretion of cytokines through the use of antibody pairs that are used in a sandwich format, similar to conventional cytokine enzyme-linked immunosorbent assays.


eosinophilia

abnormal increase in the number of eosinophils found in the blood; often found in helminthic infections, especially with tissue invasion (visceral larval migrans, trichinosis, schistosomiasis, ascariasis, strongyloidiasis); also present with other infection processes, allergic reactions (including drug induced) and with some malignant diseases.

Project: M28


EOT

ASCII character denoting “end of transmission,” indicating the end of a communication phase;

Project: AUTO01, AUTO02, AUTO03

NOTE: Part of the protocols in CLSI documents LIS01 and LIS02.


epidemiological cutoff value

the minimal inhibitory concentration/minimal effective concentration value that separates fungal populations into those with and without acquired and/or mutational resistance based on their phenotypes (minimal inhibitory concentrations)

Project: M57

NOTE: Often referred to as the "epidemiological cutoff" or "ECOFF."


epidemiological cutoff value

the minimal inhibitory concentration (MIC)/minimal effective concentration value or zone diameter value that separates microbial populations into those with and without acquired and/or mutational resistance based on their phenotypes (wild-type or non-wild-type). The epidemiological cutoff value (ECV) defines the upper limit of susceptibility for the wild-type population of isolates.

EXAMPLE:

 

Interpretive Category

ECVs

MIC (µg/mL)

Zone Diameter (mm)

Wild-type

4

20

Non-wild-type

8

19

 


epidemiological cutoff value

(ECV) minimal inhibitory concentration (MIC) value that separates bacterial populations into those with and without acquired and/or mutational resistance mechanisms based on their phenotypes (MICs). ECVs are based solely on in vitro data. ECVs are principally used in epidemiological studies seeking to monitor the emergence and evolution of non-wild-type strains. ECVs are not the same as the interpretive criteria for susceptibility testing. The term “wild-type” is used to describe strains with MIC values at or below the ECV that are presumed to possess no acquired and/or mutational resistance mechanisms. Conversely, the term “non-wild-type” is used to describe strains with MIC values above the ECV. In other words, the ECV is defined as the MIC value that best defines the estimated upper end of the wild-type population.

Project: M23


epidemiological cutoff value

the minimal inhibitory concentration (MIC) value or zone diameter value that separates microbial populations into those with and without acquired and/or mutational resistance based on their phenotypes (wild-type or non-wild-type). The epidemiological cutoff value (ECV) defines the upper limit of susceptibility for the wild-type population of isolates.

EXAMPLE:

 

Interpretive Category

ECVs

MIC (µg/mL)

Zone Diameter (mm)

Wild-type

4

20

Non-wild-type

8

19

 

 


epidemiological cutoff value

(ECV) the ECV for each agent is the value obtained by considering the wild-type distribution, the modal MIC/MEC for each distribution, and the inherent variability of the test. Usually, the ECV encompasses at least 95% of isolates in the wild-type distribution;

Project: M51

NOTE: Organisms with acquired resistance mechanisms may be included among those for which the MICs/MECs are higher than the ECV (for disk testing, those with acquired resistance mechanisms would show a zone diameter smaller than the ECV).


epidemiological cutoff value

(ECV) also called wild-type cutoff value, separates bacterial populations on the basis of minimal inhibitory concentration (MIC) distributions. ECVs are normally established on the basis of the MIC distribution data (phenotype) created from testing isolates derived from geographically diverse laboratory surveys.

Project: VET05, VET04

NOTE: ECVs are species specific (unless otherwise stated) and protocol specific, but independent of the rearing conditions and pharmacokinetics of any antibiotic treatment.


epifluorescence

method of fluorescence microscopy in which the excitation light is transmitted through the objective lens onto the specimen, and the fluorescence light is transmitted back through the objective lens to the eyepiece

Project: GP40

NOTE: Fluorescence is the immediate emission of electromagnetic radiation, typically visible light, from molecules following absorption of light with a shorter wavelength.


epigenetics

the study of heritable changes in gene expression not caused by changes in the DNA sequence;

Project: MM09

NOTE: Functionally relevant modifications of the genome that do not involve a nucleotide change.


epithelial cell abnormalities

precancerous cellular changes in the cervix that include a spectrum of cellular abnormalities such as atypical squamous cells of undetermined significance (ASC-US), atypical squamous cells—cannot exclude high-grade squamous intraepithelial lesion (ASC-H), atypical glandular cells (AGC), low-grade squamous intraepithelial lesion (LSIL), koilocytosis, HPV effect, and high-grade squamous intraepithelial lesion (HSIL), adenocarcinoma in situ (AIS), and all varieties of epithelial neoplasms;

Project: GP15

NOTE: These terms are part of the Bethesda 2001 System nomenclature. The Bethesda System is in current use in the United States and several other countries.


epitope

(determinant) the minimum molecular structure of the antigenic site that will react with a monoclonal antibody; any site on an antigen molecule at which an antibody can bind; the chemical structure of the site determining the specific combining antibody;

Project: I/LA20

NOTE: In the context of immunoglobulin E (IgE) assays, allergenic epitopes are regions on allergens that bind directly to the IgE antibody binding site. They can be detected by monoclonal antibodies to 1) determine the level of allergens of a particular specificity in an environmental specimen (eg, Der p 1 and Der f 1 in house dust); and 2) demonstrate identity and qualify extracts during the manufacturing of allergen-containing reagents.


epitope

(antigenic determinant) that portion of an antigen against which the specific binding region of a monoclonal antibody reagent is directed (H42, H43);

Project: H43, ILA29, H42, H52

NOTE 1: Epitopes may be linear sequences of as few as six amino acids or conformationally determined sections of the antigen; each antigen typically contains multiple epitopes; NOTE 2: Epitopes may be linear sequences of as few as six contiguous amino acids or conformationally determined by spatial organization of peptide domains exposed on a folded protein. Each antigen typically contains multiple epitopes.


epitope

1) the minimum molecular structure of the antigenic site that will react with a monoclonal antibody; 2) any site on an antigen molecule at which an antibody can bind; the chemical structure of the site determining the specific combining antibody

Project: ILA18, DI01, ILA23, H56, ILA28, ILA34

NOTE: In the context of IgE assays, allergenic epitopes are regions on allergens that bind directly to the IgE binding site. They can be detected by monoclonal antibodies to (1) determine the level of allergens of a particular specificity in an environmental specimen (eg, Der p 1 and Der f 1 in house dust); and (2) demonstrate identity and qualify extracts during the manufacturing of allergen-containing reagents.


epitope

(antigenic determinant) that portion of an antigen against which the specific binding region of an antibody is directed;

Project: M53

NOTE: Epitopes may be linear sequences of as few as six amino acids or conformationally determined sections of the antigen; each antigen typically contains multiple epitopes.


epitope

any site on an antigen molecule at which an antibody can bind; the chemical structure of the site determining the specific combining antibody.

Project: I/LA26


epoxy paint

paint that contains resins to allow more water and chemical resistance

Project: QMS04


epoxy resin

a poured, molded, solid material used in laboratory countertops, floors, or other surfaces

Project: QMS04


equipment

single apparatus or set of devices or apparatuses needed to perform a specific task (adapted from IEV 151-11-25);

Project: QMS13

NOTE: For the purpose of this guideline, equipment includes general purpose devices (GP37).


equipment

the articles or implements used or needed for a specific purpose or activity.

Project: M29


equipment error

a problem with equipment and/or its software used in the performance of a test or storage of samples and/or reagents leading to an unacceptable PT result


equipment master file

paper or electronic file in which records of a given instrument or piece of equipment from acquisition to decommission are maintained.

Project: QMS13


equipoise

1) an ethical basis for clinical research in which there is a state of genuine uncertainty on the part of the clinical investigator regarding the comparative therapeutic merits of each arm in a trial; 2) an alternative concept of equipoise is based on present or imminent controversy in the clinical community over the preferred treatment; according to this concept of “clinical equipoise,” the requirement is satisfied if there is genuine uncertainty within the expert medical community—not necessarily on the part of the individual investigator—about the preferred treatment

Project: GP45

NOTE: Should the investigator discover that one treatment is of superior therapeutic merit, he or she is ethically obliged to offer that treatment; the current understanding of this requirement, which entails that the investigator have no "treatment preference" throughout the course of the trial, presents nearly insuperable obstacles to the ethical commencement or completion of a controlled trial and may also contribute to the termination of trials because of the failure to enroll enough patients.


equivocal result

a test result within a specified range of the cutoff value, which cannot be interpreted as either positive or negative

Project: MM02, MM10, MM03, MM12, MM17, M55

NOTE: In molecular genetics, equivocal test results may complicate risk interpretations.


ergonomics

study of the efficiency of persons in their working environment (ISO 15190)

Project: QMS04, ISO 15190

NOTE: This term includes biomechanics, work physiology, anthropomorphism, and man-machine interfaces (ISO 15190).


ERR

an HL7 error segment (HL7 V2.6).

Project: AUTO01, AUTO02, AUTO03


erroneous result

a patient result that fails its quality requirement

Project: C24

NOTE 1: The quality requirement is usually expressed in terms of an allowable total error (TEa) requirement. If the measurement error in a patient’s result exceeds the TEa requirement, the result is erroneous; NOTE 2: May also be referred to as an incorrect result or an unacceptable result.


error

(measurement) measured quantity value minus a reference quantity value (JCGM 200:2012)

Project: EP19, H48, EP21, C24, JCGM 200:2012, POCT05, H26, GP34, QMS13, C58, MM19, C51, C56, EP27, MM20, EP26, H60, C62, C57, MM23, POCT06

NOTE 1: The concept of "measurement error" can be used both: a) when there is a single reference quantity value to refer to, which occurs if a calibration is made by means of a measurement standard with a measured quantity value having a negligible measurement uncertainty or if a conventional quantity value is given, in which case the measurement error is known, and b) if a measurand is supposed to be represented by a unique true quantity value or a set of true quantity values of negligible range, in which case the measurement error is not known (JCGM 200:2012); NOTE 2: Measurement error should not be confused with production error or mistake (JCGM 200:2012); NOTE 3: The sign of the difference must be noted; NOTE 4: Generally, a known measurement error should be corrected using the best estimate of that measurement error. The measurement uncertainty of a correction is part of the combined measurement uncertainty (JCGM 200:2008 § 2.16); NOTE 5: In C56, the “reference quantity value” would be the result from the same measurement procedure on the same sample in the absence of any hemolysis, icterus, or lipemia/turbidity interference; NOTE 6: A reference quantity is intended to be an estimate of the true quantity present in a sample; NOTE 7: For qualitative tests, an erroneous finding of the measurement procedure, eg, the presence of an analyte when the analyte is not present, and vice versa.


error

(of measurement) result of a measurement minus a true value of the measurand (VIM93);

Project: MM10, EP06, I/LA25, H54, MM12, H20

NOTE 1: Since a true value cannot be determined, in practice a conventional true value is used (VIM93); NOTE 2: When it is necessary to distinguish "error" from "relative error," the former is sometimes called absolute error of measurement. This should not be confused with absolute value of error, which is the modulus of the error (VIM93); NOTE 3: Formerly, the term "total error" was often used in CLSI documents.


error

a deviation from truth, accuracy, or correctness; a mistake.

Project: QMS24, QMS15, QMS20, GP26, QMS11, GP23

NOTE: Error in the proficiency testing (PT) process leads to an unacceptable result. Error in PT has many subtypes and classifications. Error might be classified as to when it occurred in the PT process (eg, preexamination error, examination error, or postexamination error). Error might also be classified as to the root cause of the error, as in clerical error or transcription error, equipment error, reagent error, or methodological error.


error

(of indication) of a measuring instrument indication of a measuring instrument minus a true value of the corresponding input quantity (VIM93);

Project: VIM93

NOTE 1: Since a true value cannot be determined, in practice a conventional true value is used (see 1.19 and 1.20 in VIM93); NOTE 2: This concept applies mainly where the instrument is compared to a reference standard; NOTE 3: For a material measure, the indication is the value assigned to it.


error

1) a false or mistaken result obtained in a study or experiment; 2) "Random error" (sampling error) is that due to chance, when the result obtained in the sample differs from the result that would be obtained if the entire population (“universe”) were studied; 3) "Systematic error" is that due to factors other than chance, such as faulty measuring instruments

Project: GP45

NOTE 1: It is further considered in bias; NOTE 2: Several kinds of error can occur in epidemiology, for example, due to bias; NOTE 3: Two varieties of sampling error are Type I, or alpha error, and Type II, or beta error. In an experiment, if the experimental procedure does not in reality have any effect, an apparent difference between experimental and control groups may nevertheless be observed by chance, a phenomenon known as Type I error. Another possibility is that the treatment is effective but by chance, the difference is not detected on statistical analysis—Type II error; NOTE 4: In the theory of testing hypotheses, rejecting a null hypothesis when it is actually true is called Type I error; accepting a null hypothesis when it is incorrect is called Type II error.


error

measured quantity value minus a reference quantity value (JCGM 200:2008); deviation from truth, accuracy, or correctness; includes mistakes;

Project: EP23

NOTE: It is important to note that in EP23, the term "error" includes, but is used in a much broader sense than, the VIM term "error of measurement."


error grid plot

a scatter plot for comparing measurements obtained from two measurement procedures, eg, a candidate procedure (y-axis) and a comparative procedure (x-axis). The error grid plot also includes zones indicating the potential harm associated with errors of measurement.

Project: EP27


error of measurement

See error.

Project: C51


erythrocyte

a red blood cell; the hemoglobin-containing cell of the cells found in peripheral blood (Cf. POL1/2).

Project: NRSCL8


erythrocyte indices

quantities derived (calculated) from the measured hemoglobin concentration (Hb), the red blood cell count (RBC), and the packed (red) cell volume (PCV): MCH (mean corpuscular hemoglobin) in picograms (pg), Hb (g/L) divided by RBC (..x 1012/L); MCHC (mean corpuscular hemoglobin concentration) in grams per liter (g/L), Hb (g/L) divided by PCV (L/L); and MCV (mean corpuscular volume) in femtoliters (fL), PCV (L/L) divided by RBC (..x 1012/L).


esoteric

(testing) the analysis of “rare” substances or molecules that are not performed in a routine medical laboratory.

Project: MM20


essential agreement

minimal inhibitory concentration result obtained with the antimicrobial susceptibility testing system that is within one doubling dilution step (two-fold serial) for bacteria and two doubling dilution steps for yeast from the MIC value established with the reference method (modified from ISO 20776-2)

Project: M52

NOTE 1: Another representation of the concept:  NEA •  100/N where NEA is the number of microbial isolates with an EA; N is the total number of microbial isolates tested (modified from ISO 20776-2); NOTE 2: The overall EA is expressed as a percentage (modified from ISO 20776-2).


essential agreement

(EA) MIC result obtained with the AST device that is within plus or minus one doubling dilution step from the MIC value established with the reference method. Another representation of the concept:NEA × 100/N, where NEA is the number of bacterial isolates with an EA; N is the total number of bacterial isolates tested (ISO 20776-2)

Project: ISO 20776-2

NOTE: The overall EA is expressed as a percentage (ISO 20776-2).


essential efficacy

efficacy, where, to be of benefit to a patient, the use of a medical device satisfies certain basic criteria: (i) it must not injure or otherwise harm the patient; (ii) it must perform as intended by the manufacturer; (iii) it must be used properly (ISO Guide 63-2.5).


establish

define, document (in writing or electronically), and implement.

Project: GP26


establishment

for the purposes of EP19, the determination of the performance characteristics of a new or modified measurement procedure, encompassing all stages in the measurement procedure lifecycle from feasibility through validation.

 

Project: EP19


estimate

a specific value (ie, point estimate) or values (ie, interval estimate) of an estimator;

Project: NRSCL08, C56

NOTE 1: An estimate is calculated from a specific sample or set of observations to produce a specific value or set of values; NOTE 2: Point estimate: a value that summarizes a set of data without accounting for the precision of the estimate (eg, its uncertainty).


estimator

statistic used in estimation of the parameter (ISO 3534-1)

Project: ISO 3534-1, C56

NOTE 1: An estimator differs from an estimate in that the estimator is an "equation," while the estimate is the value of that equation calculated from the sample values; NOTE 2: Estimators have different properties (eg, unbiasedness, consistency, sufficiency, and efficiency) but they do not have the property of "correctness." Thus, there is no such thing as a correct estimator.


ethylene diamine tetraacetic acid

(EDTA) one of a class of aminopolycarboxylic acids that act as sequestering (also referred to as “chelating”) agents (MM02);

Project: MM02

NOTE 1: They form soluble complexes with metal ions, removing these ions from further reactions (MM02); NOTE 2: They are negatively charged compounds (MM02).


etiologic agent

the causative agent of a disease (e.g., the microorganism that causes a specific infectious disease) (Cf. H5).

Project: H05


etiologic agent

a viable microorganism or its own toxin that causes, or may cause, human infection.

Project: GP05


evaluated method

that measurement procedure for general clinical use that is being evaluated for a possible matrix effect.


evaluation

any determination of the clinical or analytical performance characteristics of the test.

Project: EP19, H57, ILA28


evaluation

(study) a generic term for any investigation that measures the performance capabilities of an assay.

Project: M52


evaluation

process by which the referring laboratory assesses the quality of service received from the referral laboratory, during the agreement and as part of periodic review

Project: QMS05


evaluation

analysis of completed or ongoing activities that determines or supports the accountability, effectiveness, and efficiency of an activity or program

Project: QMS16, QMS14, QMS03, QMS06


evaluation of formed elements

an inclusive term encompassing the tabulation of WBC in a representative sample of human blood by a standard classification scheme (i.e., differential or “diff”), notation of the presence or absence of certain RBC abnormalities, and notation of PLT sufficiency and morphology.

Project: H20


evaluation plan

description of a planned performance evaluation (ISO 20776-2)

Project: ISO 20776-2


evaluation report

description of and conclusion from a performance evaluation (ISO 20776-2)

Project: ISO 20776-2


evaluator

individual responsible for measurement and assessment of performance, noting unresolved issues, and analysis of exercise results;

Project: GP36

NOTE 1: Selected from participating agencies, evaluators are chosen based on their expertise in the functional areas they will observe; NOTE 2: Evaluators passively assess and document participants’ performance against established emergency plans and exercise evaluation criteria; NOTE 3: Evaluators only note the actions/decisions of players without interfering with exercise flow.


event

generic term used to encompass the terms “incident,” “error,” and “accident.”

Project: QMS11


event

(proficiency testing) a single round of proficiency testing/external quality assessment testing, which may include more than one challenge (specimen or sample)

Project: QMS24, MM14


event

a single particle or cell identified by a flow cytometer.

Project: H43, H42, H52


event

an episode when the true value of the blood glucose, as measured by a stated reference method, goes below a predefined concentration (hypoglycemia) or above a predefined concentration (hyperglycemia) (POCT05).

Project: POCT05


event alarm

an instance where the device provides an indication that it has detected or is predicting a hypoglycemic or hyperglycemic event (POCT05).

Project: POCT05


event of interest

See condition of interest.


evidence of compliance

documents, records, factual statements, and other verifiable information demonstrating compliance with requirements (modified from ISO 9000)

Project: QMS17


ex vivo

a same-day in vitro analysis of biological samples.

Project: I/LA26


examination

set of operations having the object of determining the value of a property (ISO 15198)

Project: ISO 15198

NOTE: In the IVD medical device industry and in many laboratories that use IVD medical devices, examination of an analyte in a biological sample is commonly referred to as a test, assay, or analysis (ISO 15198).


examination

set of operations having the object of determining the value or characteristics of a property (ISO 15189)

Project: QMS25, GP26, QMS02, ISO 15189, ISO 18113-1, ISO 18113-2, ISO 18113-3, QMS11, GP33, GP44, POCT07, QMS06, QMS13, POCT10, QMS14, GP23

NOTE 1: In some disciplines (eg, microbiology), an examination is the total activity of a number of tests, observations, or measurements (ISO 15189); NOTE 2: In CLSI document QMS02, the term "examination" replaces the term "test"; however, for the purposes of this guideline, readers can consider the terms equivalent; NOTE 3: Laboratory examinations that determine the value of a property are called quantitative examinations; those that determine the characteristics of a property are called qualitative examinations (ISO 18113-1); NOTE 4: In clinical chemistry, laboratory examinations have been called assays or tests (ISO 18113-1); NOTE 5: Examination has replaced terms such as test, assay, and analysis in CLSI document POCT07. Subsequently, the adjectives preexamination and postexamination have replaced the adjectives preanalytical and postanalytical.


examination procedure

set of operations, described specifically, used in the performance of examinations according to a given method (ISO 15198)

Project: ISO 15198, GP26, QMS11

NOTE: In the IVD medical device industry and in many laboratories that use IVD medical devices, an examination procedure for an analyte in biological sample is commonly referred to as an analytical method, analytical procedure, or test procedure (ISO 15198).


examination process

(analytic) processes that include all activities for performing the examinations, verifying the reliability of the results, and interpreting the findings (ISO 15189)


excitation

the transition of a fluorochrome molecule from its lowest energy state (i.e., ground state) to a higher energy state following absorption of incident light (see Appendix A of I/LA24).

Project: I/LA24


excitation spectrum

the spectrum of wavelengths at which a fluorescent compound absorbs light, followed by the emission of light at a different wavelength from that of the absorbed light (SDELMT84) (Cf. DI1).

Project: SDELMT84, DI01


exclusion of venous thromboembolism

a claim that can apply to any method, the results of which can reliably exclude venous thromboembolism (VTE);

Project: H59

NOTE 1: Regarding a D-dimer reagent, studies must demonstrate that the negative predictive value (NPV), sensitivity, and coefficient of variation at the threshold have sufficient power to exclude VTE when the test is applied to patients judged to have a low or intermediate probability of VTE determined using a pretest probability (PTP) scoring algorithm; NOTE 2: As defined by the US Food and Drug Administration, a D-dimer assay with an exclusionary claim is used in conjunction with a PTP assessment to exclude the presence of a pulmonary embolism and/or a deep vein thrombosis. In addition to validating the assay’s threshold and establishing assay sensitivity, specificity, and NPVs compared with imaging studies, the clinical study must include patient follow-up to obtain clearance.


exercise

instrument to train for, assess, practice, and improve performance in prevention, protection, response, and recovery capabilities in a risk-free environment;

Project: GP36

NOTE 1: Exercises can be used for: testing and validating policies, plans, procedures, training, equipment, and interagency agreements; clarifying and training personnel in roles and responsibilities; improving interagency coordination and communications; identifying gaps in resources; improving individual performance; and identifying opportunities for improvement; NOTE 2: An exercise is also an excellent way to demonstrate community resolve to prepare for disastrous events.


exhaust air

air that is removed from an area

Project: QMS04


exogenous

developed or originating outside an organism; caused by external factors.

Project: POCT10


exogenous

developed or originating outside an organism;

Project: HS02

NOTE: Caused by external factors.


exogenous interferent

substance originating outside the body (e.g., a drug or its metabolites, a specimen preservative, or a sample contaminant) that causes interference with the analysis of another substance in the specimen.

Project: EP07


exome

all of the coding regions (exons) present in the genome of an organism or individual;

Project: MM09

NOTE: During whole exome sequencing, the protein coding regions of the genome are targeted for sequencing.


exon

region of DNA within a gene that is transcribed to the final messenger RNA and that usually contains coding information

Project: NBS05


exon

a transcribed region of a gene that is present in the mature messenger RNA.

Project: MM19


exotoxin

a soluble toxin excreted by a microorganism.

Project: NRSCL08


expandability

the ease with which a system or component can be modified to increase its storage or functional capacity.

Project: AUTO08


expanded measurement uncertainty

See expanded uncertainty.

Project: C51


expanded scale

scale in which a part of the scale range occupies a scale length that is disproportionately larger than other parts (VIM93)


expanded uncertainty

(measurement) product of a combined standard measurement uncertainty and a factor larger than the number one (JCGM 200:2012);

Project: ISO IEC Guide 99, C53, C51

NOTE 1: The factor depends upon the type of probability distribution of the output quantity in a measurement model and on the selected coverage probability (JCGM 200:2012); NOTE 2: The term "factor" in this definition refers to a coverage factor (JCGM 200:2012); NOTE 3: Expanded measurement uncertainty is termed "overall uncertainty" in paragraph 5 of Recommendation INC-1 (1980) (see the GUM) and simply "uncertainty" in IEC documents (JCGM 200:2012); NOTE 4: An expanded uncertainty is symbolized U.


expected range

as used in NBS06, the range of T-cell receptor excision circle (TREC) values in term newborns without severe combined immunodeficiency or other T-cell immunodeficiencies;

Project: NBS06

NOTE 1: The expected range is a population distribution and not an analytical parameter. The analytically valid calibration range should ideally encompass the population expected range; NOTE 2: As used in NBS06, the laboratory test result of any satisfactory newborn screening (NBS) specimen that shows TREC values at or above the predetermined cutoff. A laboratory test result that is outside of the expected range of normal/negative testing results established for a particular condition (includes carrier results) that indicates the need for further testing; NOTE 3: As used in NBS06, the laboratory test result of any satisfactory NBS specimen that shows TREC values below the predetermined cutoff would be outside the expected range, or out of range.


expected range

the range of values for a measurand in a typical healthy population

Project: NBS07

NOTE 1: The expected range is a population distribution, not an analytical parameter, that may be estimated by applying statistical methods to data from reference populations that are representative of the population being tested. The limits of the expected range may vary depending on the reference population and the statistical methods used; NOTE 2: For purposes of newborn dried blood spot (DBS) screening, results within the expected range should exclude the presence of the congenital condition that the test is used to detect, while results outside of the expected range may need to be acted upon; NOTE 3: As used in NBS07, the range of acid α-glucosidase (GAA) activity values measured in DBS specimens from newborns without Pompe disease, as opposed to laboratory test results that show GAA activity values below the predetermined cutoff (ie, a result outside of the expected range, or an out-of-range result); NOTE 4: The analytically validated calibration range should ideally encompass the population expected range and the range surrounding the value used to distinguish screen-positive and screen-negative results; NOTE 5: Expected ranges may be specified separately for subpopulations such as full-term newborns, preterm and low birth weight newborns, and older infants; NOTE 6: As used in NBS07, the laboratory test result of any satisfactory DBS specimen that shows GAA activity values at or above the predetermined cutoff is a screening result that is out of the expected range requiring follow-up (ie, a laboratory test result outside of the expected range of normal/negative testing results established for a particular condition, including carrier results, that indicates the need for additional testing).


experimental standard deviation

for a series of n measurements of the same measurand, the quantity "s" characterizing the dispersion of the results and given by the formula: xi being the result of the i-th measurement and x being the arithmetic mean of the n results considered;

NOTE 1: A valid statement of reproducibility requires specification of the conditions changed; NOTE 2: The changed conditions may include: principle of measurement, method of measurement, observer, measuring instrument, reference standard, location, conditions of use, and time; NOTE 3: Reproducibility may be expressed quantitatively in terms of the dispersion characteristics of the results; NOTE 4: Results are here usually understood to be corrected results.


expert system

a software system consisting of a knowledge base, inference engine, and explanation unit;

Project: AUTO08

NOTE: The knowledge base contains rules from experts, the inference engine uses this knowledge to reach conclusions given certain facts, and the explanation unit serves to explain how the conclusions were reached.


expert system

antimicrobial susceptibility testing software that alerts users to atypical susceptibility testing results.

Project: M52


expiration date

date after which the product, when stored under recommended conditions, should no longer be used

Project: GP39, GP34


expiration date

upper limit of the time interval during which the performance characteristics of a material stored under specified conditions can be assured;

Project: EP25

NOTE: Expiry dates are assigned to IVD reagents, calibrators, control materials, and other components by the manufacturer based on experimentally determined stability properties (adapted from EN 375:2001, §3.6).


expiry date

upper limit of the time interval during which the performance characteristics of a material stored under specified conditions can be assured (ISO 18113-1)

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3

NOTE 1: Expiry dates are assigned to IVD reagents, calibrators, control materials and other components by the manufacturer, based on experimentally determined stability properties (ISO 18113-1); NOTE 2: Guidelines for determining the stability of IVD medical devices are found in EN 13640 (ISO 18113-1); NOTE 3: Adapted from EN 375:2001, definition 3.6 (ISO 18113-1).


expiry date

See expiration date.


exploratory biomarker

type of biomarker with the most weakly established clinical validity. Exploratory biomarkers are insufficient for regulatory decision making;

Project: MM23

NOTE: They are typically used in the early stages of clinical development when hypotheses are being developed and tested, in situations of enduring uncertainty about disease targets, in situations of unrestrained inconsistency in drug response, in the selection of new compounds, or to bridge the results of animal model studies to clinical expectations.


exposure control plan

(ECP) a written plan required by OSHA that identifies those tasks and procedures in which occupational exposure may occur and that identifies the positions whose duties include those tasks and procedures identified as having occupational exposure;

Project: X03

NOTE: The ECP requires the employer to identify the individuals who will receive the training, protective equipment, vaccination, and other protections of the standard. The plan must be reviewed and updated at least annually.


exposure incident

a specific eye, mouth, other mucous membrane, nonintact skin, or parenteral contact with blood or other potentially infectious materials that results from the performance of an employee's duties.

Project: X03


expression

the conversion of the genetic instructions present in a DNA sequence into a unit of biological function in a living cell;

Project: MM13, MM19, MM22

NOTE: Expression typically involves the process of transcription of a DNA sequence into an RNA sequence followed by translation of the RNA into protein; the RNA may be spliced before translation to remove introns.


expression profiling

the measurement of the activity (ie, expression) of thousands of genes at once, to create a global picture of cellular function, often using DNA microarrays.

Project: MM19, MM22


Extensible Markup Language

(XML) a meta-language widely used on the Web and for business-to-business data exchange;

Project: POCT01

NOTE: XML is to data and information as HTML is to documents and presentations.


extensible markup language

(XML) a language widely used for data exchange in electronic communications (POCT02);

Project: POCT02

NOTE: XML is to data and information as HyperText Markup Language (HTML) is to documents and presentations (HTML is another widely utilized Internet language format) (CLSI document POCT02).


extension

the 5′ to 3′ synthesis of DNA starting from an annealed primer to generate a complementary strand of DNA.

Project: MM09


external assessment

systematic process of collecting and analyzing data conducted by an organization external to the laboratory to determine compliance with specified requirements

Project: QMS17

NOTE 1: External assessment may also be referred to as an audit, inspection, site visit, or survey; NOTE 2: For the purposes of QMS17, proficiency testing is excluded; NOTE 3: The terms “mock inspection” or “self-assessment” may be used when a laboratory assesses itself for compliance using an external assessment organization’s requirements. In this case, the laboratory is doing an “internal” assessment of itself.


external assessment organization

for purposes of QMS17, refers to all authorities providing audits, site visits, inspections, or surveys

Project: QMS17

NOTE: An external assessment organization may also be referred to as the assessment organization.


external control

in fluorescence in situ hybridization, usually a reference slide that is hybridized in parallel with the test slide;

Project: MM07

NOTE: An external normal male control slide is usually required to confirm that hybridization was successful for tests involving targets on the Y chromosome.


external control

cells of known phenotypic expression, present in a separate sample distinct for a patient or unknown sample, analyzed to define levels of antigenic expression and serve as an indicator of assay specifications being fulfilled;

Project: H52

NOTE: Positive and/or negative expression and fluorescent intensity of such cells serve as process controls. External controls are generally used when internal controls are impractical or not available, because external controls are inferior by not ensuring that the patient sample was tested in the exact sample manner.


external control

control material that mimics patient specimens and monitors the testing process from specimen application to result interpretation.

Project: MM19, MM22


external failure cost

cost occurring after delivery or shipment of a product and during or after furnishing of a service to the customer.

Project: QMS20


external quality assessment

(EQA) a program in which multiple samples are periodically sent to members of a group of laboratories for analysis and/or identification, in which each laboratory’s results are compared with those of other laboratories in the group and/or with an assigned value.

Project: C54


external quality assessment

evaluation of the laboratory’s performance on examination of samples of external origin for the purposes of determining adequacy of the laboratory’s preexamination, examination, and postexamination activities (ISO/IEC 17043);

Project: H43, ISO Guide 43-1, GP26, H42, H26, GP35, QMS14, MM14

NOTE 1: Used to establish between-laboratory and between-instrument comparability that is, if possible, in agreement with a reference standard (where one exists). External quality assessment schemes may be regional, national, or international. They may also be limited to the users of a particular instrument. It is sometimes also referred to as "proficiency testing," especially when the external agency is a regulatory agency; NOTE 2: Interlaboratory comparisons and other performance evaluations that may extend throughout all phases of the testing cycle, including interpretation of results; determination of individual and collective laboratory performance characteristics of examination procedures by means of interlaboratory comparison; NOTE 3: The primary objectives of EQA are educational and may be supported by additional elements.


external quality assessment

interlaboratory comparisons and other performance evaluations that may extend throughout all phases of the testing cycle, including interpretation of results; determination of individual and collective laboratory performance characteristics of examination procedures by means of interlaboratory comparison

Project: QMS24


external quality assessment

evaluation of the pulmonary laboratory’s performance on a specific quality method (mechanical or biologic) for the purposes of determining adequacy of the laboratory’s pretesting, testing, and posttesting activities (modified from ISO Guide 43).

Project: QMS07


external quality assessment

(EQA) determination of laboratory testing performance by means of interlaboratory comparisons;

NOTE 1: Commonly, a program periodically sends multiple specimens to members of a group of laboratories for analysis and/or identification; the program then compares each laboratory’s results with those of other laboratories in the group and/or with an assigned value, and reports the results to the participating laboratory and others; NOTE 2: Other forms of PT/EQA include: data transformation exercises, single-item testing (where one item is sent to a number of laboratories sequentially and returned to the program at intervals), and one-off exercises (where laboratories are provided with a test item on a single occasion).


external quality assessment

(EQA) evaluation of the laboratory’s performance on examination of samples of external origin for the purposes of determining adequacy of the laboratory’s preexamination, examination, and postexamination activities (ISO/IEC 17043);

Project: H52

NOTE: Used to establish between-laboratory and between-instrument comparability that is, if possible, in agreement with a reference standard (where one exists). EQA schemes may be regional, national, or international. They may also be limited to the users of a particular instrument. It is sometimes also referred to as “proficiency testing,” especially when the external agency is a regulatory agency.


external quality control

(external QC) for CLSI document C50, external quality control and assurance or proficiency testing is the evaluation of analytical performance that includes a sample for which the analyst does not know the expected measurement result;

Project: C50

NOTE 1: A “blank” QC sample is not acceptable as an external (“blind”) QC material, although it is appropriate as an internal (“bench”) QC material; NOTE 2: Standards are acceptable external (“blind”) QC specimens provided the analyst does not know the expected result for the standard (CLSI document C50).


external RNA control

the RNA species that are added to an RNA sample prior to enzymatic manipulations with the purpose of qualitatively assessing technical performance of the amplification or hybridization or the performance of the assay platform.

Project: MM16


extracorporeal life support

(ECLS) a procedure used to treat infants with a variety of conditions such as sepsis, pneumonia, diaphragmatic hernia, and meconium aspiration

Project: NBS03

NOTE: Similar to a heart/lung bypass machine, ECLS can be used for days or weeks and provides circulation and oxygenation of blood, allowing the patient’s heart and lungs to rest and heal. For the purposes of NBS, it is essentially a continuous transfusion of red cells and other blood components.


extracted ion chromatogram

(EIC or XIC) a postacquisition process by which the ion current of one (or several) m/z values acquired in a spectral scan mode are selected and displayed as a function of time (C50);

Project: C50

NOTE: This function simulates selected ion monitoring (SIM), but offers no enhancement of sensitivity (C50).


extracted ion chromatogram

chromatogram created by plotting the intensity of the signal observed at a chosen m/z value or series of values in a series of mass spectra recorded as a function of retention time (IUPAC 2006).

Project: C43


extraction

See nucleic acid extraction.

Project: MM19


extraction blank

a blank that incorporates only the extraction agents in subsequent testing.


extraction hood

cabinet or cover above a laboratory device for the extraction of air or fumes directly to the exterior of a building, which prevents their general circulation(modified from ISO 15190)

Project: QMS04


extraction hood

cabinet or cover above a laboratory device for the extraction of air or fumes which prevents their general circulation (ISO 15190)

Project: ISO 15190


extra-label use

the use of an approved human or animal drug in animals in a manner that is not in accordance with the approved labeling.

Project: VET06, VET01


extrapolate

to estimate (the value of a variable) outside the tabulated or observed range;

Project: H54

NOTE: (H54) INRs above 4.5 would be extrapolated, while those between 1 and 4.5 would be interpolated.


extremely low birth weight

(ELBW) birth weight < 1000 g

Project: NBS03


extrinsic blood coagulation pathway

the activation of Factor X by Tissue Factor/VIIa complex.

Project: POCT14


extrinsic factor pathway

mechanism of the coagulation pathway in vivo is tissue factor binding to activated Factor VII which activates Factor X and Factor IX

Project: H48

NOTE 1: Activated Factor X converts prothrombin to thrombin, with activated Factor V, merges with extrinsic pathway into common pathway; NOTE 2: This pathway is measured by the prothrombin time; NOTE 3: Activation of Factor IX by VIIa/tissue factor complex occurs in vivo only. Factor IX is not assessed in the prothrombin time.


exudate

as a subtype of pleural fluid, due to inflammation and characterized by high protein and presence of cells.

Project: C49


exudate

the accumulation of a fluid having a high concentration of protein in a body cavity caused by increased capillary permeability usually secondary to inflammation.

Project: C49, M54


exudate

a fluid with a high concentration of protein or cells that accumulates in a body cavity as a result of increased capillary permeability.

Project: H56


eyewash station

unit designed to allow people to flush their eyes and face with water in case of a chemical or biological spill

Project: QMS04


eyewash station

unit designed to allow people to flush their eyes and face with water in case of a chemical or biological spill


F cell

a non-nucleated erythrocyte or red cell containing hemoglobin F in addition to other hemoglobin types;

NOTE: It is found in all individuals of all ages, as distinct from fetal red cells, which contain hemoglobin F as the sole or predominant hemoglobin type and are only found in the in utero fetus, newborn, and pregnant female circulation or fluids containing blood.


face velocity

the speed of the air moving into a cabinet or hood measured at the front opening

Project: QMS04


facilitator

individual responsible for keeping participant discussions on track with the exercise design objectives and making sure all issues and objectives are explored as thoroughly as possible within time constraints during a discussion-based exercise.

Project: GP36


factor inhibitor

antibodies that neutralize the activity of a specific clotting factor

Project: H48

NOTE: Some inhibitors are so strong that they may affect other factors.


factor sensitivity

(of a reagent) responsiveness of the reagent to one or more specific factor deficiencies

Project: H48

NOTE: Variation in responsiveness is likely due to differences in the activator and/or phospholipids used in the reagent.


Factor VIII

a plasma glycoprotein which, when activated by thrombin, functions as a cofactor in the conversion of Factor X to Factor Xa;

Project: H51

NOTE: It is normally carried and stabilized by von Willebrand factor; its reduction in plasma is the cause of hemophilia A.


Factor VIII

a plasma glycoprotein which, when activated by thrombin, functions as a cofactor in the conversion of Factor X to Factor Xa;

NOTE: It is normally carried and stabilized by von Willebrand factor; its reduction in plasma is the cause of hemophilia A.


factorial experiment

experimental design in which all possible treatment combinations formed from two or more factors, each being studied at two or more levels, are examined so that interactions (differential effects) as well as main effects can be estimated.

Project: EP07


facultative anaerobe

a microorganism that can multiply in the presence or absence of oxygen.

Project: M56


failure

in the broadest sense, a case when the system does not meet user or customer expectations

Project: GP47, EP18, POCT07, QMS06, QMS15, QMS20

NOTE 1: This includes the inability to perform its intended functions satisfactorily or within specified performance limits; NOTE 2: Errors of measurement and errors of use are subsets of failures.


failure

in the broadest sense, a case when the system does not meet the user’s expectation;

Project: EP23

NOTE 1: This includes the inability to perform its intended functions satisfactorily or within specified performance limits; NOTE 2: Errors of measurement and errors of use are subsets of failures.


failure cause

physical or chemical processes, design defects, quality defects, part misapplication, or other processes which are the basic reason for failure or which initiate the physical process by which deterioration proceeds to failure.

(MIL-STD-1629A. Procedures for Performing a Failure Mode, Effects and Criticality Analysis. 24 November 1980.)


failure effect

consequence(s) a failure mode has on the operation, function, or status of an item. Failure effects are classified as local effect, next higher level, and end effect.

(MIL-STD-1629A. Procedures for Performing a Failure Mode, Effects and Criticality Analysis. 24 November 1980.)


failure mode

manner by which a failure is observed; generally describes the way the failure occurs and its effect on equipment operation

Project: GP47, EP18, POCT07, EP23

(MIL-STD-1629A. Procedures for Performing a Failure Mode, Effects and Criticality Analysis. 24 November 1980.)


failure mode and effects analysis

(FMEA) analysis technique for system reliability, based on assumptions of possible failure states of each component of a device or system (IEC 60812).

Project: POCT02


failure modes and effects analysis

(FMEA) systematic review of a system or process that examines how failures can affect performance;

Project: QMS20

NOTE 1: FMEA involves identification of potential failure modes, determining the consequences of each failure, and reviewing the control measures implemented to prevent or detect the failure; NOTE 2: If estimating the risk of the failures and the risk of harm is part of the analysis, the technique is called “failure modes, effects, and criticality analysis.”


failure modes and effects analysis

(FMEA) 1) systematic review of an instrument system or process that examines how failures can affect the instrument system or process, the test results, or the testing personnel; 2) systematic review of a system or process that examines how failures can affect performance;

Project: EP18, POCT07, QMS06

NOTE 1: FMEA involves identification of potential failure modes, determining the consequences of each failure, and reviewing the control measures implemented to prevent or detect the failure; NOTE 2: If estimating the risk of the failures and the risk of harm is part of the analysis, the technique is called "failure mode, effects, and criticality analysis" (FMECA); NOTE 3: FMEA is considered a "bottom-up" analysis; NOTE 4: See CLSI document EP18 for further information.


Failure Reporting and Corrective Action System

(FRACAS) a process by which failures are identified and analyzed so that corrective actions can be implemented.

Project: EP18


failure reporting, analysis, and corrective action system

(FRACAS) a process whereby a system is tested, and failures are observed and classified by severity and frequency of occurrence;

Project: POCT07

NOTE 1: The failures are ranked by criticality, the product of severity, and frequency of occurrence; NOTE 2: The most important problems are corrected; NOTE 3: See CLSI document EP18 for further information.


false negative

“in-range” result in an affected newborn


false negative

an observation for which no event alarm occurs, although there is a relevant symptomatic event.

Project: MM19


false negative

a negative test result for a disease or condition when the disease or condition is present.

Project: M53, MM22


false negative

See false-negative result.

Project: I/LA28, MM01


false negative

an observation for which no event alarm occurs, although there is a relevant hypoglycemic or hyperglycemic event (POCT05).

Project: POCT05


false positive

a positive test result for a disease or condition when the disease or condition is not present;

Project: M47, M53, MM19, MM22

NOTE: For blood cultures, 1) a culture that yields a microbial isolate(s) that is determined not to be the cause of sepsis, or 2) a culture with objective evidence of microbial growth (i.e., an instrument signal that indicates microbial growth) but for which subcultures and stains are negative.


false positive

“out-of-range” result in an unaffected newborn


false positive

an observation for which an event alarm occurs, but there is no relevant hypoglycemic or hyperglycemic event (POCT05).

Project: POCT05


false positive

See false-positive result.

Project: I/LA28, MM01


false-negative (clinical) newborn dried blood spot screening result

a screen-negative result reported in an affected newborn 

Project: NBS07

NOTE: As used in NBS07, a screen-negative result of a newborn DBS screening algorithm (based on the detected acid α-glucosidase enzyme activity above the cutoff) reported for a newborn later diagnosed with Pompe disease.


false-negative fraction

ratio of subjects who have the disease, but who have a negative test result, to all subjects who have the disease; FN / (FN + true positive [TP]); equivalent to (1 − sensitivity).

Project: EP24


false-negative rate

the rate needed for calculating negative predictive value incorporating prevalence;

Project: MM12

[1 - P (T + | D + ) ] P (D +) ÷ 1 - P(T +)
Where: T = test result, D = disease/state of interest, and P(D+) = prevalence of disease or state of interest (i.e., probability that the disease or state of interest is present in the target population).


false-negative rate

(FNR) rate of negative test results for a disease or condition when the disease or condition is present.

Project: POCT07


false-negative ratio

(FNR) the ratio of subjects who have the disease, but who have a negative test result (FN), to all subjects who have the disease (FN + True positives; TP); FNR = FN/(FN + TP)

Project: GP10, MM12


false-negative result

a negative test result for a disease or condition when the disease or condition is present.

Project: MM21


false-negative result

a negative test result for a subject in whom the condition of interest is present (as determined by the diagnostic accuracy criteria) (EP12)

Project: EP33, EP12

NOTE: In the context of EP33, a false negative result indicates that a delta check alert did not occur when there was a specimen issue or patient condition change that should have been identified.


false-negative result

a negative test result for a patient or specimen who is positive for the condition or constituent in question.

Project: MM12, MM01, MM17


false-negative result

(FN) a negative test result for a patient or specimen that is positive for the condition or constituent in question (Cf. POL1/2).

Project: POL1/2, I/LA23, H20


false-negative result

“in-range” result in an affected newborn

Project: NBS03


false-negative result

negative test result for a subject in whom the disease or condition of interest is present;

Project: EP24, H60

NOTE 1: Alternatively, a person who has a condition but is incorrectly identified as negative for having the condition; NOTE 2: The term is often unclear in lupus anticoagulant testing because a gold standard test is lacking.


false-negative result

(FN) a negative test result for a patient or specimen that is known or subsequently proved to be positive for the condition or constituent in question.

Project: I/LA28


false-negative screening test

negative result in an affected child

Project: NBS05

NOTE 1: For quantitative tests such as immunoreactive trypsinogen, this refers to an “in-range” result in an affected child; NOTE 2: For qualitative tests such as DNA analysis, this may include failure to detect cystic fibrosis transmembrane conductance regulator mutations.


false-positive (clinical) newborn dried blood spot screening result

a screen-positive result reported in an unaffected newborn

Project: NBS07

NOTE: As used in NBS07, the positive result of a newborn DBS algorithm (based on the deficiency of acid α-glucosidase activity) that is obtained for a newborn who does not have Pompe disease (including carriers for a GAA gene mutation).


false-positive fraction

ratio of subjects who do not have the disease, but who have a positive test result, to all subjects who do not have the disease; FP / (FP + true negative [TN]); same as (1 − specificity).

Project: EP24


false-positive rate

the rate needed for calculating positive predictive value incorporating prevalence;

Project: MM12

P (T+ | D- ) [1 - P (D+)] ÷ P(T +)
Where: T = test result, D = disease/state of interest, and P(D+) = prevalence of disease or state of interest (i.e., probability that the disease or state of interest is present in the target population).


false-positive rate

(FPR) proportion of unaffected individuals with positive test results.

Project: ILA25


false-positive rate

(FPR) rate of positive test results for a disease or condition when the disease or condition is not present.

Project: POCT07


false-positive ratio

(FPR) the ratio of subjects who do not have the disease, but who have a positive test result (FP), to all subjects who do not have the disease (FP + True negatives; TN); FP/(FP + TN)

Project: GP10, MM12


false-positive result

a positive test result for a disease or condition when the disease or condition is not present.

Project: MM21


false-positive result

(FP) a positive test result for a patient or specimen that is negative for the condition or constituent in question (NRSCL8).

Project: NRSCL8, I/LA23, MM12, H20

   Test Method Results
Reference Method ResultsPositive Negative
PositiveTP (True Positive) FN (False Negative)
NegativeFP (False Positive) TN (True Negative)


false-positive result

(FP) a positive test result for a patient or specimen that is negative for the condition of interest or constituent in question (MM12).

Project: MM12, MM17


false-positive result

a positive test result for a subject in whom the condition of interest is absent (as determined by the diagnostic accuracy criteria) (EP12)

Project: EP33, EP12


NOTE: In the context of EP33, a false positive result refers to a delta check alert that does not identify the type of change of interest to the laboratory.


false-positive result

“out-of-range” result in an unaffected newborn

Project: NBS03


false-positive result

positive test result for a subject in whom the disease or condition of interest is absent;

Project: EP24, H60

NOTE 1: Alternatively, a person who does not have the condition but is incorrectly identified as positive for having the condition; NOTE 2: The term is often unclear in lupus anticoagulant testing because a gold standard test is lacking.


false-positive result

a positive test result for a patient or specimen who is negative for the condition or constituent in question.

Project: MM01


false-positive result

(FP) a positive test result for a patient or specimen that is known or subsequently proved to be negative for the condition or constituent in question.

Project: I/LA28


false-positive screening test

positive result in an unaffected child

Project: NBS05

NOTE 1: For quantitative tests such as immunoreactive trypsinogen, this refers to “out-of-range” results in an unaffected child; NOTE 2: For qualitative tests such as DNA analysis, this may include detection of cystic fibrosis transmembrane conductance regulator (CFTR) mutations in a carrier or detection of CFTR mutations that are not actually present.


family history

the genetic relationships and medical history of a family;

Project: MM19

NOTE: When represented in diagram form using standardized symbols and terminology, it is usually referred to as a pedigree.


Faraday cage

an enclosure surrounding an electrochemical measurement system that serves as a shield against interference from ambient electromagnetic signals.

Project: C39


fastidious

requiring specialized conditions for growth.

Project: M54, M56


fasting glucose

the concentration of glucose in whole blood or plasma after refraining from consumption of food or sugar-containing beverages for at least eight hours;

Project: POCT13

NOTE: In contrast, see nonfasting glucose.


fatality

usual term for deceased person resulting from an accident or disaster, to be distinguished in emergency parlance from “casualty.”

Project: GP36


fault

state of an item, characterized by the inability to perform a required function, excluding inabilities due to preventive maintenance, other planned actions, or lack of external resources.

Project: EP23


fault tree analysis

(FTA) systematic review of an instrument or system to identify potential sources of failure that starts by assuming a main system failure and determines what could cause it;

Project: EP18, POCT07

NOTE 1: FTA is considered a "top-down" analysis; NOTE 2: FTA is more efficient than FMEA for analyzing combinations of failure events and human-use failures; NOTE 3: FTA and FMEA are often used together to evaluate complex systems for a comprehensive top-down and bottom-up risk analysis; NOTE 4: See CLSI document EP18 for further information.


fault tree analysis

(FTA) systematic review of a system or product to identify sources of potential failure; particularly useful in safety and reliability analyses;

Project: ISO 15198

NOTE First, a list of potential failure modes is developed. For each, an analysis is conducted to (1) determine the primary causes; (2) the secondary causes behind the primary causes; and (3) possibilities to mitigate the primary and the secondary causes.


fault tree gates

BASIC – the lowest level event in a tree branch; AND – the output occurs if and only if all the input (lower in tree) events occur; OR – the output occurs if and only if at least one of the input (lower in tree) events occur; PAND – the output occurs if and only if all input (lower in tree) events occur in a particular order.

Project: EP18


Fc

the portion and/or fraction of the IgG molecule derived from papain digestion that consists of the C-terminal half of the H chain. Certain biological properties are associated with this fragment, which sometimes can be easily induced to form crystals (Cf. DI1).

Project: DI01


Fc receptor

a protein found on the surface of certain cells—including natural killer cells, macrophages, neutrophils, lymphocytes, and mast cells—that contribute to the protective functions of the immune system;

Project: ILA29

NOTE: The name is derived from the receptor’s binding specificity for a part of an antibody known as the Fc (fragment, crystallizable) region. Fc receptors bind to antibodies that are attached to infected cells or invading pathogens. Their activity stimulates phagocytic or cytotoxic cells to destroy microbes, or infected cells by antibody-mediated phagocytosis or antibody-dependent cell-mediated cytotoxicity.


F-distribution

{a parametric} probability distribution of a continuous random variable, which can take any value from 0 to + ¥ (ISO 3534-1-1.41);

Project: ISO 3534-1-

NOTE: This is the distribution of the quotient of two independent X 2 {chi-squared} distributed random variables, each one divided by its number of degrees of freedom (ISO 3534-1-1.41).


feasibility assessment

consideration of a potential measurement procedure system, by the manufacturer, concerning various issues that are relevant to the advisability of developing a new measurement procedure system;

Project: EP19

NOTE 1: Issues may include the potential market for the test, client expectations, and strategic plans for the institution; NOTE 2: CLSI does not offer relevant guidance in this area.


feature

a defined segment of single-stranded nucleic acid immobilized on a solid substrate (i.e., microarray) that is used to identify specific DNA or RNA molecules having a complementary sequence.

Project: MM12


feature

a single miniaturized hybridization reaction area on the solid surface of the microarray where multiple copies of the single nucleic acid probe are immobilized.

Project: MM22


feed water

the water that is introduced into a purification process

Project: GP40


Felgett advantage

for weak signals, if multiple mass spectra are averaged, the signal-to-noise ratio for a peak corresponding to an analyte signal will improve when compared to random chemical or electronic noise present in the spectrum (CLSI document C50);

Project: C50

NOTE: The increase in signal-to-noise ratio observed is proportional to the square root of the number of scans averaged (CLSI document C50).


fetal lung immaturity

the absence of lung maturity in a fetus, primarily due to an insufficient quantity of pulmonary surfactant that is nearly always associated with preterm birth.

Project: C58


fetal lung maturity

the presence of a functional fetal lung as indicated by an adequate amount of pulmonary surfactant.

Project: C58


fetal red blood cell

a nucleated normoblast (red blood cell precursor) or non-nucleated erythrocyte containing hemoglobin F as the predominant hemoglobin type and produced by an in utero fetus;

NOTE: It may be found in maternal circulation, as red cells, which contain hemoglobin F as the predominant hemoglobin type, but distinct from those F cells present in adult circulation in the nonpregnant individual.


fibrinogen

a plasma glycoprotein that is converted to fibrin by thrombin and supports platelet aggregation.

Project: H51


fibrinogen assay

the assay of fibrinogen concentration commonly measured by the rate at which it is converted to fibrin by the action of thrombin;

Project: H30

NOTE 1: It is described in CLSI/NCCLS document H30; NOTE 2: Other methodologies include precipitation/gravimetric, immunological, and nephelometric procedures.


fiducial

refers to the use of geographic markings on a microarray that permit the orientation of that device as to left, right, up, and down;

Project: MM12

NOTE 1: Fiducial markings are typically fluorochrome labeled oligonucleotides comprised of irrelevant sequence; such markers do not hybridize to the target sequence, and are therefore detected as fluorescent spots on the microarray independent of the controls or of the test samples; NOTE 2: Fiducial markings are typically fluorochrome labeled oligonucleotides comprised of irrelevant sequence; such markers do not hybridize to the target sequence, and are therefore detected as fluorescent spots on the microarray independent of the controls or of the test samples.


fiducial error

(of a measuring instrument) error of a measuring instrument divided by a value specified for the instrument (VIM93);

NOTE: The specified value is generally called the fiducial value, and may be, for example, the span or the upper limit of the nominal range of the measuring instrument.


field

one specific attribute of a record which may contain aggregates of data elements further refining the basic attribute

Project: LIS02


field correction

correction applicable to a device already released by the manufacturer;

Project: HS11

NOTE: A correction may be performed without removing the device to another location or returning it to the manufacturer.


filariform larvae

slender, infective larvae of Strongyloides stercoralis and hookworm

Project: M28


filler

a person or service that produces the observations requested by the placer.

Project: AUTO01, AUTO02, AUTO03


filtration

a purification process in which the passage of fluid through a porous material results in the removal of impurities based on the physical interaction of the impurities with that porous material

Project: GP40


fine needle aspiration

the process of obtaining a sample of cells and bits of tissue for examination by applying suction through a fine needle attached to a syringe (MM17).

Project: MM17


finished device

for the purposes of EP19, a clinical laboratory measurement procedure that is suitable for use or capable of clinical testing whether or not it is packaged or labeled as such.

Project: EP19


fire egress

route used to get out of a building in case of a fire

Project: QMS04


fire rating

rating of a wall or door used to protect an area from a fire for a certain amount of time

Project: QMS04

NOTE: Normally listed in hours of 1, 2, 3, or as smoke containment.


firewall

a security component/device protecting a network (as a configuration with high confidentiality level) against areas of low confidentiality level (eg, the Internet); it can also be used within a network to protect a specific sensitive part of a network (eg, an LIS) (CLSI document POCT02);

Project: POCT02

NOTE 1: The primary function of a firewall is to let “good” traffic pass through while “bad” traffic gets blocked by analyzing and filtering the “good” data packages (CLSI document POCT02); NOTE 2: Firewalls intercept attacks before the operating system can even acknowledge them (CLSI document POCT02); NOTE 3: A software firewall (often called “personal firewall”) is used to protect a specific computer against the outside. This software is nestled between the network drivers and the operating system, relieving the operating system from the filtering task and protecting it from getting infected (CLSI document POCT02).


firewall

an internetwork gateway that restricts data communication traffic to and from one of the connected networks (the one said to be “inside” the firewall) and thus protects that network’s system resources against threats from the other network (the one that is said to be “outside” the firewall). (RFC 2828)

Project: AUTO09


firmware

computer programs contained permanently in a hardware device (as read-only memory).

Project: ILA33


first isolate

refers to the initial microbial isolate of a particular species recovered from a patient during the time period analyzed regardless of body source, specimen type, or antimicrobial susceptibility profile;

Project: M39

NOTE: If analysis of a subset of isolates is being performed (eg, isolates from blood cultures or methicillin-resistant Staphylococcus aureus [MRSA] isolates), "first isolate" would refer to the first isolate in that particular subset (ie, the patient’s first blood or MRSA isolate).


first morning specimen

(overnight, early-morning, eight-hour) a urine specimen collected immediately upon awakening in the morning;

Project: GP08

NOTE: This is also known as an overnight, early-morning, or 8-hour specimen. (Cf. GP8)


first-order kinetics degradation

a product degradation reaction rate that can be described by a linear differential equation, leading to an exponential relationship between the product concentration and the reaction time.

Project: EP25


first-tier testing

primary testing that in some instances may require additional testing before reporting the primary test result, or subsequent to reporting the primary test result, as the standard of care dictates

Project: GP49

NOTE: The second-tier test is also referred to as a “reflex test.”


fishbone diagram

also called a “cause-and-effect” or “Ishikawa” diagram; causes are arranged according to their level of importance or detail, resulting in a depiction of relationships and hierarchy of events;

Project: C53

NOTE: This tool can help to clarify the causes that affect results and the relationships between a number of causes on the overall effect.


fishbone diagram

diagram that shows the causes of a certain event;

Project: EP23

NOTE: Common uses of the diagram are product design and quality defect prevention, to identify potential factors causing an overall effect.


FITC

the form of fluorescein most commonly conjugated to ligand molecules;

Project: I/LA24

NOTE: This is often used to describe any covalent fluorescein conjugate regardless of the actual conjugation chemistry used.


fitness for purpose

a term used to indicate that a method or service fits the analyst’s defined purpose for that measurand.

Project: X05


fixation

the process by which biological and autolytic processes of a biological specimen are halted by chemical means;

Project: I/LA28

NOTE: The goal of fixation is to result in a piece of tissue or cellular preparation that is stable for storage and analysis later.


fixed casework system

premanufactured casework system that is fixed (bolted) to the floor, wall, and/or each other

Project: QMS04


fixed cost

a periodic cost that remains more or less unchanged irrespective of output level or sales revenue (BusinessDictionary.com)


flagging

an instrument function identifying a sample or blood film for further attention or review.

Project: H20


flame mode

in the flame mode, a factor can be applied to results generated by direct ISE systems that makes the results comparable to those generated by indirect systems for patient specimens normal in protein and lipid content.

Project: C29


flammable liquid

a liquid with a flash point less than 38°C (100°F)

Project: QMS04


flash point

the lowest temperature that the vapor above a liquid will ignite when an ignition source is introduced

Project: QMS04


flection

the point at which the vertical (straight) walls of the specimen container bend to form the base.

Project: AUTO01, AUTO02


flexibility

the ease with which a system or component can be modified for use in applications or environments other than those for which it was specifically designed.

Project: AUTO08


flexible casework system

premanufactured casework system that is easily changeable in aspects, including countertop height and storage components

Project: QMS04


flood shower

a shower located in laboratories that is used for emergency purposes, eg, in case of accidental chemical spills, biological spills, or fire

Project: QMS04

NOTE: also called an emergency shower


floor plans

graphic drawings created to show the layout of a space from the perspective of looking down upon it

Project: QMS04


flow chart

diagram, often using geometric symbols, showing the sequence of activities and decisions made in a process; also commonly referred to as “process map.”

Project: QMS02, QMS18


flow crossmatch

a test for compatibility between recipient and donor by testing recipient cells with donor cells;

Project: ILA29

NOTE: If the recipient has antibody against antigens present on the donor cells, binding will occur. A labeled secondary antibody is added, which will attach to the bound antibody on the cells. Detection of antibody binding is achieved by comparing the level of fluorescence from the secondary antibody between the test serum and the negative control.


flow cytometer

a microphotometer in which the sample consists of a stream of cells or other particles, ideally flowing in single file through a sensing region from which optical signals are collected as each particle is illuminated one at a time.

Project: I/LA24


flow cytometry

a methodologically oriented subdiscipline of analytical cytology that measures cells in suspension in a liquid vehicle as they pass, typically one cell at a time, by a measurement station;

Project: H44

NOTE: The measurement represents transformations of changes in the output of a detector (or detectors) due to changes in scattered light, absorbed light, light emitted (fluorescence) by the cell, or changes in electrical impedance, as the cell passes through the measuring station.


flow cytometry

a methodologically oriented subdiscipline of analytical cytology that measures cells in suspension in a liquid vehicle as they pass, typically one cell at a time, by a measurement station.

NOTE: The measurement represents transformations or changes in the output of a detector (or detectors) due to changes in scattered light, absorbed light, light emitted (fluorescence) by the cell, or changes in electrical impedance, as the cell passes through the measuring station.


flow cytometry

the analysis of cells or microparticles on an instrument in which one cell or particle at a time passes through the aperture and is analyzed by detecting fluorescent staining.

Project: ILA29


fluorescein isothiocyanate

(FITC) the most common fluorochrome used for cell immunophenotyping;

Project: H42, H43, H52

NOTE: Fluorescein conjugates absorb maximally at approximately 490 nm, close to the 488-nm emission of argon lasers, and emit maximally near 525 nm. Each conjugated fluorescein molecule adds a net negative charge to the antibody, and therefore may change its potential binding characteristics.


fluorescein isothiocyanate

(FITC) a chemical that is commonly used to label proteins and, when excited at an appropriate wavelength (typically a “blue” 488 nm argon laser) of ultraviolet light, will emit a fluorescent signal detectable by appropriate instrumentation;

Project: I/LA26

NOTE: FITC is excited maximally at approximately 490 nm with an emission maximum at 520 nm.


fluorescence

brief electromagnetic radiation emitted as a result of absorption of radiation (photons) by an atom, molecule, or ion (NRSCL8);

Project: NRSCL8, I/LA24

NOTE: Generally, fluorescent radiation has a longer wavelength than the absorbed radiation.


fluorescence

brief visible electromagnetic radiation signal emitted because of absorption of radiation (photons) by an atom, molecule, or ion.

Project: I/LA28


fluorescence energy transfer immunoassay

a type of sandwich fluorescence immunoassay of an antigen with multivalent antigenic determinants in which antibodies are labeled with donor and acceptor fluorescence markers;

Project: H59

NOTE 1: The reaction of at least two antibodies with the targeted antigen, resulting in the approximation of these two determinants closer than a critical distance of 50 to 70 Angstroms that quenches the fluorescence; NOTE 2: The reduction in fluorescence emission is proportional to the antigen concentration.


fluorescence enhancement

the increased fluorescent emission due to a change in the environment of the excited molecules.

Project: NRSCL08


fluorescence excitation transfer

nonradiative energy exchange between a fluorescer (donor) and a quencher (acceptor);

Project: NRSCL08

NOTE: Caused by a dipole-dipole resonance energy transfer mechanism that exists when there is overlapping of the fluorescer emission spectrum and the acceptor absorption spectrum.


fluorescence immunoassay

(FIA) a generic term for an immunoassay in which the analyte content of the sample is measured by the amount of fluorescence from bound antibody or antigen

NOTE: Immunoassays that use a fluorogenic enzyme substrate (e.g., methylumbelliferone phosphate) can also be classified as fluorescence immunoassays.


fluorescence immunoassay

a type of immunoassay in which the antigen or, as in the case of D-dimer, antibody is labeled with a fluorescent compound that emits light at a wavelength when excited by a light at a different wavelength or by a chemical reaction.

Project: H59


fluorescence in situ hybridization

(FISH) a technique in which genes are localized in chromosome preparations of cell nuclei using fluorescently labeled probes. In the context of molecular diagnosis of hematological malignancies, FISH is used to detect chromosomal rearrangements of specific genes.

Project: MM05


fluorescence intensity

(FI) 1) the reading on an instrument response scale caused by detection of a portion of the fluorescence emission from excited fluorochromes; 2) a measure of fluorescence radiant power (I/LA24).

Project: ILA24


fluorescence intensity

a measurement of the amount of fluorochrome bound to a particle or cell;

Project: H42, H43, H52

NOTE: Increasing intensity is reflected in a fluorescence signal appearing in a higher channel number. Under appropriate conditions, fluorescence intensity can be related to the number of binding sites a cell has for a particular fluorochrome-conjugated reagent.


fluorescence quenching

any interaction of the fluorescence molecule with a solvent, solutes, or other environmental factors that lowers the fluorescence quantum yield;

Project: NRSCL08, I/LA24

NOTE: As used in this document, fluorescence quenching may also be due to decreased absorptivity of the fluorochrome.


fluorescence resonance energy transfer

(FRET) the principle of transfer of fluorescent light energy from one dye to another dye, a process which can serve as a label for nucleic acid probes;

Project: MM03

NOTE 1: Fluorescent energy can be transferred from one dye to another dye located on the same probe (eg, 5′ nuclease assay probes or molecular beacons) or from one dye on one probe to another dye on a second probe that hybridize in a head-to-tail configuration to target nucleic acid (eg, FRET hybridization probes); NOTE 2: For some probe designs, the transferred energy is absorbed and emitted at a different wavelength. For other probes, the transmitted energy is quenched and no light emission occurs.


fluorescence resonance energy transfer

a type of fluorescent immunoassay, in which a donor molecule (which is usually the substrate) is excited, electronically or by an external light source, and instead of emitting light, the excitation energy transfers to a nearby acceptor molecule (which is the product);

Project: H59

NOTE: The excited states of one or both of the donor and acceptor can decay with fluorescence emission. When energy transfer is observed, a reduction in the emission intensity of the donor/substrate with a concomitant increase in the emission intensity from the acceptor/product is observed. The intensity of the longer wavelength emission from acceptor/product is proportional to its amount.


fluorescence system

a fluorescer and other components necessary to produce the measured fluorescence signal that is modulated by the analyte.

Project: NRSCL08


fluorescence yield

product of the concentration of a fluorochrome in solution or suspension and the quantum yield of the fluorochrome molecule.

Project: I/LA24


fluorescer

a substance that fluoresces when excited by electromagnetic radiation (Cf. DI1).

Project: DI01, I/LA23


fluorochrome

reagent that emits visible light when irradiated with excitation light of a shorter wavelength (ISO 19001)

Project: ISO 19001, MM22


fluorochrome

a substance that fluoresces when excited by electromagnetic radiation;

Project: I/LA24

NOTE: This term is synonymous with, and in I/LA24 supersedes, the terms "fluorescer," "fluorophore," and "fluorophor."


fluorochrome

chemical compound that has the property of absorbing light at one wavelength and emitting light of a longer wavelength

Project: H44


fluorochrome

a chemical compound that has the property of absorbing light at one wavelength and emitting light of a longer wavelength.

Project: H44


fluorochrome-ligand conjugate

(FLC) as used in this document, a reagent for staining receptor bearing microparticles in which a fluorochrome is covalently attached to a ligand for that particular receptor;

Project: I/LA24

NOTE: The ligand is most often an antibody raised against the receptor.


fluorograph

graphical representation of the results obtained from real-time polymerase chain reaction (PCR) amplifications that use fluorescent dyes;

Project: MM03

NOTE: It plots fluorescence or change in fluorescence as a function of PCR cycle number.


fluorometer

a generic term for any instrument used to measure fluorescence intensity and possibly other qualities of fluorescence emission such as spectral distribution or anisotropy;

Project: I/LA24

NOTE: This term is synonymous with, and in I/LA24 supersedes, the term "fluorimeter."


fluorometer

an instrument that measures the intensity of fluorescence (Cf. DI1).

Project: DI01


fluorophore

fluorescent molecule that absorbs light energy and is promoted to an excited state that is released as fluorescence, in the absence of a quencher, when the fluorophore falls back to the ground state and releases the excess energy.

Project: MM03, MM22


FN

the number of false-negative results (EP12).

Project: EP12


follow-up

actions taken to ensure that a person whose test results are screen positive or invalid receives appropriate further tests and evaluation in a timely fashion; and actions taken that ensure the newborn screening system evaluates the effectiveness of screening

Project: NBS02


follow-up

actions taken to ensure that a newborn whose screening test results are incomplete, “out-of-range,” or “invalid” receives appropriate further tests and evaluation in a timely fashion (short term), and actions taken to ensure that the newborn screening system can evaluate the effectiveness of screening (long term)

Project: NBS05


follow-up algorithm

the logic process used to determine whether, and the extent to which, a particular newborn needs additional screening, a diagnostic evaluation, or treatment and the next steps that are communicated to the newborn’s health care provider.

Project: NBS07


follow-up algorithm

the logic process used to determine whether, and the extent to which, a particular baby needs additional newborn screening, a diagnostic evaluation, or treatment. The follow-up screening algorithm is the set of processes that determines recommendations for next steps that are communicated to the baby’s health care provider.

Project: NBS06


font

a specific member of a type family such as roman, boldface, or italic type;

Project: AUTO12

NOTE: Point size may or may not be an integral component of a font description, depending on whether or not a scalable outline font is being used.


foot-candle

(fc) unit of light on a surface one square foot in areas with a uniform distribution of a specific amount

Project: QMS04


force majeure

any situation such as an “act of God” (ie, natural disaster), war, strike or labor dispute, embargo, government order, or any other such event for which neither the supplier nor the organization is liable for any failure of or delay in performance of an agreement for the period that such failure or delay is due to causes beyond its reasonable control

Project: QMS21


forensic testing

testing performed for administrative or legal purposes and not for patient care

Project: C52


form

a paper or electronic document on which the results from the performance of a procedure or other information are captured; a completed form becomes a record.

Project: QMS02


form

a paper or electronic document on which information, data, or results are captured;

Project: QMS25, QMS06, GP26

NOTE: Once completed, a form becomes a record.


form

a paper or electronic document on which data or information are captured;

Project: QMS21, QMS15, QMS20

NOTE: Once completed, a form becomes a record.


formalin-fixed, paraffin-embedded

describes tissue that has undergone a method for preserving cell morphology as well as nucleic acids and proteins in a tissue or cytology specimen.

Project: MM23


forward angle light scatter

(FALS) measurement of light at a low radial angle relative to the incident light source (H42, H43);

Project: H42

NOTE: Measured values are a function of the cross sectional area and refractive index of a cell or particle and the wavelength used for measurement. It is commonly used as an estimate of the relative size of a cell or particle (H42, H43).


forward group

tests RBC with reagent anti-A and anti-B to determine the red cell antigens present on the red cell;

Project: ILA33

NOTE 1: A positive reaction of hemagglutination indicates the presence of the corresponding antigen on RBC; a negative reaction (no hemagglutination) indicates the absence of the corresponding red cell antigen; NOTE 2: Formerly known as forward type or front type.


forward scatter

measurement of light at a low radial angle relative to the incident light source;

Project: H52

NOTE: Measured values are a function of the cross-sectional area and refractive index of a cell or particle and the wavelength used for measurement. It is commonly used as an estimate of the relative size of a cell or particle.


fosmid

a type of cosmid (ie, a hybrid plasmid that contains a lambda phage cos sequence) that is based on the bacterial F-plasmid. These constructs can hold DNA inserts up to 40 kb.

Project: MM21


fosmid

a type of cosmid that is based on the bacterial F-plasmid. These constructs can hold DNA inserts up to 40 kb.

Project: MM09


four phases of emergency management

four activities that together and sequentially summarize the emergency planning cycle: mitigation, preparedness, response, recovery.

Project: GP36


FP

the number of false-positive results (EP12).

Project: EP12


fraction

a part of the whole of anything.


fractional carboxyhemoglobin

(FCOHb) the substance fraction of carboxyhemoglobin. (Cf. C25, C41).

Project: C25, C41


fractional oxyhemoglobin

the oxyhemoglobin substance fraction of the total hemoglobin;

NOTE 1: Formally termed the oxyhemoglobin fraction of total hemoglobin; NOTE 2: Of the two abbreviated forms of this term, "fractional oxyhemoglobin," or "oxyhemoglobin fraction," the former is the recommended version because it reads, sequentially, identically to the formal symbol. The term "oxyhemoglobin" alone is also acceptable if unambiguous in the context; NOTE 3: "Fractional" and "saturation," or "saturation as % of total hemoglobin," should not be used because of the potential for confusion and awkwardness in phraseology. (Cf. C12, C25)


fragile site

a nonstaining gap in the chromatin of a metaphase chromosome, eg, the fragile site at Xq27 in the fragile X syndrome.

Project: MM19


fragment analysis

electrophoretic analysis of DNA that has been digested with one or more restriction endonucleases.

Project: MM19


frame

a subdivision of a message, used to allow periodic communication housekeeping, such as error checks and acknowledgments.

Project: LIS01


free fraction

the fraction of total analyte not bound to receptor.


free hormone fraction

a number between zero and unity indicating what proportion of hormone is in free, nonprotein-bound form;

Project: C45

NOTE: Alternatively, the free fraction may be expressed as a percentage, which in the case of FT4 leads to more convenient figures.


free immunoglobulin E

human immunoglobulin E (IgE) that circulates in blood in an unbound state, free of therapeutically administered humanized Immunoglobulin G anti-IgE, soluble IgE receptors, or other binding factors

Project: I/LA20

NOTE: Research assays for free IgE that use the alpha chain of the high affinity fragment crystallizable-epsilon receptor (FcεR1) receptor as the IgE detection reagent have been developed but are not yet commercially available.


free thyroid hormone index tests

all tests in which an estimate of total T4 (TT4) or total T3 (TT3) is required;

Project: C45

NOTE: This definition concerns two distinct categories of tests. First, those in which the total hormone measurement is combined either with a THBR test (e.g., T3-uptake) or a measurement of TBG. This approach leads to indices that correlate with, but cannot be considered as unambiguous estimates of the true FTH concentration. The second category comprises techniques like indirect ED, UF, SD, and gel equilibration that may yield valid estimates of the FTH fraction so that, after multiplication with the total concentration, a valid approximation of the true FTH concentration is obtained. It is recommended to reserve the term "FTI" for the first category of tests only, since it would be rather confusing when at least in theory potential reference measurement procedures would be classified under that name.


freedom from bias

(of a measuring instrument) ability of a measuring instrument to give indications free from systematic error (VIM93)


frequency

the number of occurrences of a given type of event or the number of observations in a specified class (ISO 3534-1/93-2.11).

Project: ISO 3534


frequency distribution

the empirical relationship between the values of a characteristic {and/or random variable} and their frequencies or their relative frequencies (ISO3534-1/93-2.15).

Project: ISO 3534-1


frequency distribution

the empirical relationship between the values of a characteristic and the frequencies or their relative frequencies.

Project: ISO 3534


fresh isolate

isolate recovered from a clinical sample within the previous seven days that has not been frozen or subcultured more than five times (ISO 20776-2) 

Project: ISO 20776-2


full mutation

in trinucleotide repeat disorders, the expanded allele that reaches or exceeds a size threshold such that the abnormal phenotype is expressed, eg, greater than 200 CGG repeats in the fragile X syndrome.

Project: MM19


full-scale exercise

multiagency, multijurisdictional activity involving actual deployment of resources in a coordinated response as if a real incident had occurred;

Project: GP36

NOTE 1: A full-scale exercise tests many components of one or more capabilities within emergency response and recovery, and is typically used to assess plans, procedures, and coordinated responses under crisis conditions; NOTE 2: Characteristics of a full-scale exercise include mobilized units, personnel, and equipment; a stressful, realistic environment, and scripted exercise scenarios.


full-scan acquisition

method of mass spectral data acquisition that detects all masses within a specific mass range

Project: NBS04


fully automated system

a system in which sample and reagent uptake, sample and reagent interaction, chemical and biological analysis, reaction measurement, result interpretation, and result report are mechanized.

Project: ILA33


fume hood

see extraction hood


fume hood

See extraction hood.


function checks

activities performed to evaluate critical operating characteristics (eg, stray light, zeroing, electrical levels, optical alignment, background counts, counting efficiency) according to the accepted method of operation for each type of device or instrument;

Project: QMS13

NOTE: Function checks must be within the manufacturer’s established limits before examinations are conducted (42 CFR 493).


functional exercise

activity designed to evaluate capabilities and multiple functions using a simulated response;

Project: GP36

NOTE 1: A functional exercise is typically used to: evaluate the management of emergency operations centers, command posts, and headquarters; and assess the adequacy of response plans and resources; NOTE 2: Characteristics of a functional exercise include simulated deployment of resources and personnel, rapid problem solving, and a highly stressful environment.


functional hemoglobin

hemoglobin forms in which the iron is in the ferrous (II) state and that can bind reversibly with molecular oxygen components.


functional oxygen saturation

See oxygen saturation.


functional resolution

the size of copy number variant (CNV) that can be detected in a particular genomic region;

Project: MM21

NOTE 1: It is dependent upon both the number of probes for a particular CNV necessary for a confident detection and the marker density in a given genomic region; NOTE 2: The smallest reliably detected copy number aberration or absence of heterozygosity region for a microarray platform.


functional sensitivity

the measurand concentration at which precision of a measurement procedure, under stated experimental conditions, meets a stated performance requirement;

Project: EP17

NOTE 1: It is typically determined from a precision profile; NOTE 2: The term "limit of quantitation" with stated requirement for accuracy is recommended.


fungemia

the presence of fungi (yeasts or molds) in the bloodstream.

Project: M47


gag multimer

an engineered reagent used to identify antigen-specific T-cells that recognize the core protein of HIV.

Project: I/LA26


game

see exercise.

Project: GP36


gamete donor

the donation of an egg or sperm for the intention of achieving a pregnancy;

Project: MM19

NOTE 1: Egg donation is the process by which a woman provides one or several (usually 10–15) eggs for purposes of assisted reproduction or biomedical research. For assisted reproduction purposes, egg donation involves the process of in vitro fertilization, because the eggs are fertilized in the laboratory. After the eggs have been obtained, the role of the egg donor is complete; NOTE 2: Sperm donation refers to provision by a man, known as a sperm donor, of his semen with the intention that it be used to achieve a pregnancy in a woman without the process of sexual fertilization. Pregnancies are most commonly achieved via sperm donation by the use of artificial insemination.


gamma globulin

one of several groups of blood plasma proteins, divided into fractions, based on electrophoretic mobility somewhat slower than beta globulin (Cf. DI1).

Project: DI01


gap analysis

a technique that businesses use to determine steps to take to move from its current state to its desired future state

Project: QMS19


gas exchange indices

the several quantities that may be used to assess pulmonary gas exchange and intrapulmonary shunting;

Project: NRSCL08

NOTE 1: These are determined by calculation from both measured and estimated values of other quantities; NOTE 2: The correlation between each of the indices and the shunt fraction, Qsp/Qt is relatively low (r2 < 0.5); NOTE 3: They include: (1) arterial oxygen tension-inspired oxygen fraction ratio - the ratio of the measured tension of oxygen in arterial blood to the fraction of inspired oxygen; (2) alveolar oxygen tension - the partial pressure of oxygen in alveolar gas as estimated by the alveolar air equation; this quantity is required for calculation of some gas exchange indices, such as the oxygen tension gradient and ratio; (3) alveolar-arterial oxygen tension difference (A//aDO2//[PAO2 - PaO2]) - the gradient between the estimated oxygen tension for alveolar air and the oxygen tension measured in arterial blood; (4) arterial-alveolar oxygen tension ratio (PaO2/PAO2//a/A ratio) - the ratio of the oxygen tension as measured in the arterial blood to the estimated oxygen tension in alveolar gas; also designated the a/A ratio, which if unambiguous in context, is acceptable (Cf. C12-A).


gate

a set of parameters used to electronically select particular cells for evaluation;

Project: I/LA26, H42, H43, H52

NOTE 1: Typically, a region of interest is defined based on one set of parameters (such as FSC vs SSC), and other parameters (such as fluorescence) are evaluated only for cells within that defined region; NOTE 2: Typically, a region of interest is defined based on one set of parameters (such as CD45 vs SS), and other parameters (such as fluorescence and light scatter) are evaluated only for cells within that defined region.


gate

an electronic partition by the flow cytometer to select a population of interest for analysis.

Project: ILA29


gauging

(of a measuring instrument) operation of fixing the positions of the scale marks of a measuring instrument (in some cases of certain principal marks only), in relation to the corresponding values of the measurands (VIM93)


gel electrophoresis

a process that causes separation of molecules in an electric field within a matrix of agarose or polyacrylamide according to size and charge

Project: MM02


gel electrophoresis

separation of molecules in an electric field within a matrix of agarose or polyacrylamide according to size and charge.

Project: MM10, MM18, MM09, MM12, MM01


gel electrophoresis

separation of molecules, according to size and charge, in an electric field within a matrix of agarose or polyacrylamide.

Project: MM22


gene

a chromosomal segment that codes for a single polypeptide chain or a structural molecule (MM18).

Project: MM18


gene

a chromosomal segment that codes for a single polypeptide chain.

Project: MM02


gene dosage

measuring the quantity of a variety of analytes, including DNA, RNA, and protein, by comparison with a known standard; can be used to determine the number of copies of a sequence of DNA (ie, to test for duplication and deletion mutations), either by visual comparison of band intensity or numerical quantification by densitometry (MM17);

Project: MM17

NOTE: If extra copies of a gene are present, intensity is greater than 100% on a gel or film; whereas, if one copy of the gene is missing, the intensity is approximately 50% (MM17).


gene panel

a battery of genes or variants that cause indistinguishable phenotypes and are concurrently sequenced using massively parallel sequencing. The gene panel is sequenced or investigated as a group and generally associated with the same clinical condition, and/or used in the same clinical indication tested in a similar manner.

Project: MM09


gene rearrangement

the normal process by which immunoglobulin genes are assembled into DNA sequences capable of coding for immunoglobulin or T-cell receptor genes;

Project: MM02

NOTE: Gene rearrangement occurs as a normal part of the developmental maturation of B- and T-lymphocytes.


gene scanning

analysis of DNA by indirect means, as opposed to direct identification by sequencing, aimed at identifying regions of gene sequence alterations

Project: NBS05

NOTE: Scanning is applied as a two-tier process in which a first step (eg, denaturing gradient gel electrophoresis, single-stranded DNA, single-stranded conformation polymorphism [heteroduplex], denaturing high-performance liquid chromatography, temperature gradient capillary electrophoresis, or conformational sensitive gel electrophoresis) identifies a portion of an individual’s gene that differs from a known normal pattern, such as by differences in migration on a gel under specified conditions. This technique can, in pieces (or groups of pieces in a multiplex amplification), cover either the entire coding region or select regions of a gene. Once a region that is different from normal is identified, direct sequencing of a small amplified DNA fragment can localize the specific sequence alteration (base pair substitution, insertion, or deletion).


gene sequencing

process of recording the exact sequence of nucleotides in a given gene fragment

Project: NBS05


generator

a firm or institution that creates waste.

Project: GP05


generic ISI

an ISI determined for a thromboplastin that is not instrument-specific (ie, determined for a group of instruments that uses the same general method for endpoint detection, such as manual, photo-optical, or mechanical methods) (H54).

Project: H54, H47


genetic counseling

process of helping people understand and adapt to the medical, psychological, and familial implications of genetic contributions to disease. This process integrates the following: 1) interpretation of family and medical histories to assess the chance of disease occurrence or recurrence; 2) education about inheritance, testing, management, prevention, resources, and research; and 3) counseling to promote informed choices and adaptation to the risk or condition.

Project: MM20


genetically modified organism

microorganism that has had its genetic material purposely modified or altered through genetic engineering in a manner that does not occur naturally.

Project: M29


genome

the complete genetic content of an organism (MM13).

Project: MM13, MM18


genomic DNA

total deoxyribonucleic acid from an organism or a cell, which includes both the chromosomes within the nucleus and the DNA in mitochondria (MM17).

Project: MM17


genomics

the study of the genome, which includes genome mapping, gene sequencing, and gene function.

Project: MM13


genotype

1) the genetic makeup of an organism, or group of organisms, with reference to a single trait, set of traits, or an entire complex of traits (RHUD1.7CD); 2) the specific allelic composition of a gene, or set of genes, established at the DNA level.

Project: MM10, MM12, MM01, MM17, MM22


genotype

the specific allelic composition of a gene or set of genes, established at the DNA level

Project: MM17


genotype

the genetic makeup of an organism, or group of organisms, with reference to a single trait, set of traits, or an entire complex of traits;

Project: MM09

NOTE: The specific allelic composition of a gene, or set of genes, established at the DNA level.


genotype phenotype correlation

the association between the presence of a certain mutation or mutations (genotype) and the resulting pattern of abnormalities (phenotype).

Project: MM19


geometric mean

the mean of n positive numbers obtained by taking the nth root of the product of the numbers (H57);

Project: H57

NOTE: A detailed description and an example can be found in CLSI document H47.


germicide

a general term that indicates an agent that kills pathogenic microorganisms on inanimate surfaces

Project: I17


germicide

a substance that destroys microorganisms, especially pathogens;

Project: M29

NOTE: Technically, a germicide does not destroy spores.


germline

the cell line from which the egg or sperm cells (gametes) are derived. A germline mutation is the presence of an altered gene within the egg or sperm (germ cell), such that the altered gene can be passed to subsequent generations.

Project: MM19


gestational age

time from the first day of the last menstrual period (LMP);

Project: ILA25

NOTE: This can be determined directly by asking a woman the date of her LMP (ie, using her “dates”) or indirectly by using an ultrasound scan measurement (usually the crown-rump length [CRL] or a biparietal diameter [BPD]). Ultrasound measures that confirm the LMP provide the most accurate assessment of gestational age. Gestational age can be calculated to the day. When tabulated gestational age is grouped into “completed” weeks; so for example, 16 weeks 0 days to 16 weeks 6 days are all classified as 16 completed weeks.


gestational age

the length of the pregnancy at birth (measured from the first day of the last menstrual period), in weeks

Project: NBS05


gestational age

the length of the pregnancy at birth (measured from the first day of the last menstrual period), in weeks

Project: NBS03


global efficacy

a combined level of safety provided by unconditional, conditional, and descriptive safety plus efficacy (ISO Guide 63-2.6).


Global System for Mobile Communications

(GSM) standard for digital mobile communications, with a capability for international roaming;

Project: AUTO09

NOTE: GSM is operated in the 900-MHz and 1800-MHz frequency bands in Europe and Asia, and in the 800-MHz and 1900-MHz frequency bands in the U.S. Traditional GSM handsets allow data rates of up to 14.4 kbit/s. Some extensions (HCSCD, GPRS) may increase the transfer data rate.


globulin

a group of proteins that occurs in plant and animal tissue, characterized by low solubility in distilled water (as compared with albumin) and increased solubility when salt is added.

Project: DI01


glucose level

the specific concentration of glucose in the sample matrix specified in the device claim (eg, glucose in interstitial fluid, glucose in capillary blood obtained at a specified anatomical site, or glucose in plasma) (POCT05).

Project: POCT05


glucose meter

a small, portable, medical device used for determining the approximate concentration of glucose in the blood at a specific point in time

Project: POCT17

NOTE: It can be a component of a blood glucose monitoring system that converts the product of a chemical reaction into the glucose concentration of the sample. 


glucose monitoring

the process of measuring glucose in vivo or in vitro over time for the purpose of gathering clinical information (POCT05).

Project: POCT05


glucose monitoring system

a combination of an instrument, a disposable element, and ancillary materials such as lancing devices and control solutions used for monitoring glucose levels in blood or other body fluids

Project: POCT17, POCT13

NOTE 1: ISO 15197 defines a blood-glucose monitoring system as a "measuring system consisting of a portable instrument and reagents used for the in vitro monitoring of glucose concentrations in blood"; NOTE 2:  A system intended for the quantitative measurement of blood glucose as an aid to monitor the effectiveness of glycemic control.


glycogen

principal carbohydrate reserve; glucosan of high molecular weight; found within vacuoles of many of the protozoa

Project: M28


glycohemoglobin

(GHB) the generic term for a family of compounds arising from the nonenzymatic reaction between the free aldehyde group of glucose or other sugars and the unprotonated form of the free amino groups of hemoglobin;

Project: C44

NOTE: The terms "glycated hemoglobin" and "glycohemoglobin" are synonymous.


glycolysis

process by which glucose is converted into lactate with the subsequent formation of ATP (SDELMT84);

NOTE: In vitro, this process can lower glucose concentration in a blood sample by the action of red blood cells. (Cf. POL1/2)


glycolytic inhibitor

agent that inhibits the use of glucose by blood cells

Project: GP39, GP34


glycoprotein Ib-IX

(GPIb-IX) the major platelet membrane receptor for von Willebrand factor.

Project: H51


glycoprotein Ib-IX

(GPIb-IX) the major platelet membrane receptor for von Willebrand factor

Project: H51


glycoprotein Ib-IX

(GPIb-IX) the major platelet membrane receptor for von Willebrand factor.

Project: H51


goal

broad statement describing a desired future condition or achievement without being specific about how much and when

Project: QMS16, QMS03, QMS06, QMS14, QMS20

NOTE 1: An example is “Improve customer service”; NOTE 2: An example is “Improve laboratory service”; NOTE 3: “Goal” is not synonymous with “objective.”


gold standard

a nonspecific term that indicates that a process or material(s) is the best available approximation of the truth (Cf. GP10);

Project: GP10, ILA23, EP12, MM17

NOTE: Its use is deprecated.


good laboratory practice


good laboratory practice

(GLP) embodies a set of principles that provides a framework within which laboratory studies are planned, performed, monitored, recorded, reported, and archived;

Project: I/LA28

NOTE: These studies are undertaken to generate data by which the hazards and risks to users, consumers, and third parties, including the environment, can be assessed for pharmaceuticals, agrochemicals, cosmetics, food and feed additives, contaminants, novel foods, and biocides. GLP helps assure regulatory authorities that the data submitted are a true reflection of the results obtained during the study, and therefore can be relied upon when making risk/safety assessments.


good-quality spectrum

an information-rich spectrum with many well-defined peaks and high signal-to-noise

Project: M58


graded challenge

See graded survey.

Project: MM14


graded event

See graded survey.

Project: MM14


graded survey

survey/event/challenge in which the participants’ results as a group meet predetermined goals (eg, 80% consensus) and are valid, and from which the individual participant’s performance can be evaluated or scored.

Project: MM14


gram-negative

refers to bacteria that do not retain the primary violet stain in the decolorization step in the procedure originally described by Gram

Project: GP40


gram-positive

refers to bacteria that absorb and retain the primary violet stain in the decolorization step in the procedure originally described by Gram

Project: GP40


grand mean

overall mean calculated after multiple runs or days of analysis (EP10).

Project: EP10, POL1/2


granulation

the quality of being homogeneous;

NOTE: As applied to blood, it refers to cellular elements.


granuloma

a chronic inflammatory tissue response characterized by activated histiocytes and possibly giant cells.

Project: M54


graphical symbol

visually perceptible figure used to transmit information independently of language (ISO/IEC 80416-1)

Project: ISO/IEC 80416-1, ISO 18113-1


gravimetry

the process of measuring the mass (weight) of a substance. (Cf. POL1/2)

Project: POL1/2


grind

to homogenize by friction (eg, with a sterile mortar and pestle or tissue grinder).

Project: M54


gross square footage

(GSF) square footage that includes usable space and the space necessary to accommodate walls, columns, shafts, plumbing, and other support features

Project: QMS04


grossing station

equipment used in the dissection of gross anatomy specimens

Project: QMS04


group purchasing organization

(GPO) an entity that helps health care providers achieve savings and efficiencies by aggregating purchasing volume and using that leverage to negotiate discounts with manufacturers, distributors, and other suppliers

Project: QMS21


growth medium

cell culture nutrient solution intended to promote adhesion of dispersed (eg, trypsinized) cells to a culture vessel surface and/or to support mitotic division of cells

Project: M41


growth promotion

administration of an antimicrobial, usually as a feed additive, over a period of time to growing animals that results in improved physiologic performance (i.e., weight gain, feed conversion);

NOTE: Although this has been sometimes referred to as "subtherapeutic" use, it implies only a lower dosage and longer duration of medication than for a therapeutic use of a feed additive.


guanine-cytosine content

the percentage of nitrogenous bases on a DNA molecule that are guanine or cytosine.

Project: MM22


guanine-cytosine skew

a measure of the evenness of guanine (G) and cytosine (C) distribution between the two strands of a DNA sequence calculated from the numbers of G and C nucleotides using the formula (G − C) / (G + C).

Project: MM09


guidelines

principles and procedures to set basic requirements; recommended actions


gypsum board

wall or ceiling sheets made from gypsum

Project: QMS04

NOTE: Also called "sheet rock."


Hamming distance

the minimum number of substitutions needed to change one sequence string to another.

Project: MM09


hand hygiene

the action of hand cleansing by washing hands with soap and water or a soap solution or by the application of a waterless antimicrobial hand rub (eg, alcohol or chlorhexidine-based hand rubs), to the surface of the hands

Project: POCT04

NOTE: When performed correctly, hand hygiene results in the reduction of microorganisms.


hands-free

describes something operable without the use of a person’s hands

Project: QMS04

NOTE: The term is generally used to describe handwash sinks and can include electric-eye operators or foot pedal controls.


handwash sink

a sink that is dedicated to handwashing only and is not used for any procedural purposes

Project: QMS04


haplotype

a combination of alleles that are at linked loci on a chromosome and which, because of linkage, are inherited as a group.

Project: MM09


hapten

a substance with a single epitope that can react with a previously existing antibody but cannot stimulate more antibody production unless combined with other molecules {i.e., it is not immunogenic by itself} (Cf. DI1).

Project: DI01


hard ducted

describes air ducts that connect directly to an instrument, so fumes or contaminants can be transported directly to the outside of the building

Project: QMS04


hard ionization

an ionization process that produces extensive fragmentation (C50).

Project: C50


hard stop

a clinical decision support tool that cannot be overridden at the point of computerized order entry


hard wired

describes electrical or communication wires directly connected to the unit instead of through an outlet

Project: QMS04


hardware

the physical computer equipment, connections, and wiring to connect a communication network (POCT02).

Project: POCT02


hardware token

a small physical device that an authorized user of computer services is given to aid in authentication;

Project: AUTO09

NOTE: The token can also store cryptographic keys and biometric data.


harm

injury or damage to the health of people, or damage to property or the environment (ISO/IEC Guide 51)

Project: ISO 14971, QMS11, EP18, ISO 18113-1, EP23

NOTE: In EP23, damage to property or the environment is considered harmful only if that damage directly harms people.


harmonization

in glycohemoglobin (GHB) testing, the process by which GHB test results among laboratories are made comparable to a common reference (C44).

Project: C44


harmonization

an understanding so as to develop confidence in an acceptance of assessment using different approaches and a willingness to work towards convergence of these methods (WHO);

NOTE: Towards this end, harmonization will be addressed as a two-step process: in the short term, to increase/strive for worldwide understanding of various methods used; in the long term, to identify areas for convergence and work toward this convergence (WHO).


harmonization

the process of recognizing, understanding, and explaining differences while taking steps to achieve uniformity of results, or at a minimum, a means of conversion of results such that different groups can use the data obtained from assays interchangeably.

Project: I/LA28


hash function

an algorithm that computes a value based on a data object (such as a message or file; usually variable-length; possibly very large), thereby mapping the data object to a smaller data object (the “hash result”) which is usually a fixed-size value. (RFC 2828)

Project: AUTO09


hazard

potential source of harm (ISO 15190)

Project: ISO 15190, POCT02, M29, HS11, ISO 18113-1, ISO 18113-2, ISO 18113-3, ISO/IEC Guide 51:1999, ISO/DIS 14971, QMS11, EP18, EP23

NOTE 1: A hazard may harm either a healthcare provider or a healthcare recipient (ISO/IEC Guide 51); NOTE 2: Depending on the measurand and the nature and extent of the measurement error, an incorrect IVD examination result could be considered a hazard. See ISO 14971 for guidelines.


hazard

for purposes of emergency planning, an occurrence or situation which is both plausible and potentially disruptive of services. See hazard vulnerability analysis.

Project: GP36


hazard analysis

study of the chains of cause and effect between identified hazards, the hazardous situations to which they might lead, and the resulting harm;

Project: EP18

NOTE 1: The purpose of a hazard analysis is to derive sufficient information for the assessment of the risks involved and the identification of preventive measures; NOTE 2: For additional information on hazard analysis, see ISO 14971.


hazard notice

a formal communication that may be distributed from a variety of different sources alerting the public to a possible hazard.

Project: HS11


hazard reduction

an active or passive process, procedure, or method that reduces or eliminates the hazard of the waste;

Project: GP05

NOTE: Examples include storing radioactive waste for decay, autoclaving infectious waste, and neutralizing waste mineral acids.


hazard statement

phrase assigned to a hazard class and category that describes the nature of the hazard or hazards (see A Guide to the Globally Harmonized System of Classification and Labelling of Chemicals [GHS]).

Project: GP17


hazard vulnerability analysis

an analysis of the various risks or emergencies likely to be experienced by a community, facility, or laboratory, and the severity of impact potentially resulting from each;

Project: GP36

NOTE: An emergency operations plan should be developed in response to a hazard vulnerability analysis.


hazardous material

any substance that poses an immediate or potential threat to human health or to the environment, and which requires special handling, processing, or disposal because it is toxic, infectious, carcinogenic, explosive, or reactive.

Project: ISO 14971


hazardous material

as referenced in Department of Transportation regulations, a substance or material that has been determined by the Secretary of Transportation to be capable of posing an unreasonable risk to health, safety, and property when transported in commerce, and which has been so designated;

Project: GP05

NOTE: Hazardous wastes, regulated medical wastes, and most forms of low-level radioactive waste are hazardous materials.


hazardous situation

circumstance in which people, property, or the environment are exposed to one or more hazards (ISO/IEC Guide 51)

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3, ISO/IEC Guide 51, ISO/DIS 14971, EP18

NOTE: Incorrect IVD examination results can contribute to a hazardous situation for a patient. See ISO 14971:2007, Annex H (ISO 18113-1).


hazardous waste

waste that is potentially harmful to human beings, property, or the environment (ISO 18113-1)

Project: ISO 15190, ISO 18113-1, ISO 18113-2, ISO 18113-3

NOTE: Includes waste that is flammable, combustible, ignitable, corrosive, toxic, reactive, injurious, or infectious (ISO 18113-1); EXAMPLES: Used reagent strips contaminated with human blood; reagent solution containing sodium azide; decommissioned instruments containing heavy metals (ISO 18113-1).


hazardous waste

regulated hazardous waste is chemical waste that singly, or in combination, poses an immediate or potential threat to human health or to the environment and that, singly or in combination, requires special handling, processing, or disposal;

Project: GP05

NOTE: This includes chemical wastes that may be flammable, explosive, reactive, corrosive, toxic, carcinogenic, infectious, bioconcentrative, potentially lethal, irritating, or strongly sensitizing.


hazardous waste

waste that is potentially flammable, combustible, ignitable, corrosive, toxic, reactive, or injurious to people or the environment (ISO 15190)

Project: M29


hazards and operability study

(HAZOP) risk analysis method based on guidewords used for the proactive investigation of failure conditions within a system or device (IEC 61882).

Project: POCT02


HAZMAT

See hazardous material.

Project: GP05


HAZMAT employee

as referenced in Department of Transportation regulations, a person who is employed by a HAZMAT employer and directly affects hazardous materials (HAZMAT) transportation safety, including an owner-operator of a motor vehicle that transports HAZMAT; and any other employed person (including a self-employed person) who loads, unloads, or handles HAZMAT; tests, reconditions, repairs, modifies, marks, or otherwise represents packagings as qualified for use for the transportation of HAZMAT; prepares HAZMAT for transportations; is responsible for safety of transporting HAZMAT; or operates a vehicle used to transport HAZMAT.

Project: GP05


HAZMAT employer

as referenced in Department of Transportation regulations, a person who uses one or more of its employees in connection with transporting HAZMAT in commerce; causing HAZMAT to be transported or shipped in commerce; or representing, marking, certifying, selling, offering, reconditioning, testing, repairing, or modifying packagings as qualified for the use in transportation of HAZMAT.

Project: GP05


Hb

See hemoglobin.


HDL cholesterol

cholesterol bound to a high-density lipoprotein


health care organization

HCO all components of an organization where the IVD is installed.


health care organization

all aspects of an organization where the in vitro diagnostic system is installed (eg, LIS).

Project: AUTO11


health care provider

individual authorized to deliver health care to a patient (ISO 17593)

Project: ISO 17593, GP33, POCT08, GP23

NOTE 1: In ISO 17593, a health care provider is an individual, such as a doctor, nurse, technician, technical specialist, or appropriate assistant who provides instruction to a self-testing patient; NOTE 2: This is a global term used to describe a person obtaining the sample and can include phycisian, nurse, medical technologist, laboratory assistant, respiratory therapist, care assistants, and phlebotomists.


health care provider

individual authorized to deliver health services to a patient (ISO 18113-1)

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3

EXAMPLES: physician, nurse, ambulance attendant, dentist, diabetes educator, laboratory technician, medical assistant, medical specialist, respiratory care practitioner (ISO 18113-1).


health information exchange

the electronic sharing of health-related information among organizations within a region, community, or hospital system according to nationally recognized standards

Project: QMS19


Health Level 7

(HL7) an ANSI-accredited standards development organization focused on messages that support the exchange of clinical data (www.hl7.org) (CLSI document POCT02);

Project: POCT02

NOTE: The HL7 standard specifies a message framework and structure that enables disparate health care information systems to exchange data (CLSI document POCT02).


Health Level 7

(HL7) the Health Level 7 organization (www.hl7.org), an ANSI-accredited standards development organization focused on messaging to support the exchange of clinical and administrative healthcare data;

Project: POCT01

NOTE: The HL7 standard specifies a transport-independent messaging framework and structure that enables disparate healthcare information systems to exchange data.


Health Level Seven

(HL7) the highest level (application) communications model for open systems interconnection (OSI);

Project: AUTO01, AUTO02, AUTO07, AUTO03

NOTE: Level 7 supports security checks, participant identification, availability checks, exchange mechanism negotiations, and data exchange structuring.


health services research

the multidisciplinary field of scientific investigation that studies how social factors, financing systems, organizational structures and processes, health technologies, and personal behaviors affect access to health care, the quality and cost of health care, and ultimately our health and well-being

Project: GP45

NOTE: Its research domains are individuals, families, organizations, institutions, communities, and populations.


Healthcare Informatics Standards Board

(HISB) an organization that coordinates activities of all standards developers in the healthcare informatics area of ANSI organizations.

Project: AUTO01, AUTO02, AUTO07


Healthcare Information Technology Standards Panel

(HITSP) an organization that coordinates activities of all standards developers in the health care informatics area of ANSI organizations. http://www.hitsp.org/

Project: AUTO03


heat-induced antigen retrieval

the process of antigen retrieval mediated by heating the tissue section, on a slide in a buffer;

Project: I/LA28

NOTE 1: Heat sources include water baths, steamers, pressure cookers, autoclaves, and microwave ovens. Buffers include an agent such as citrate, at a specified pH (commonly neutral [pH 6-7] or high pH [pH 9-11]), and may include detergents or chelators such as ethylenediaminetetraacetic acid or ethylene glycol tetraacetic acid; NOTE 2: See antigen retrieval.


heavy polypeptide chain

a polypeptide with a molecular mass of about 50,000 Daltons;

Project: NRSCL08

NOTE 1: When paired with another heavy chain and linked to two light chains, it forms the immunoglobulin molecule; NOTE 2: The heavy chains of the IgA, IgD, IgE, IgG, and IgM immunoglobulins are denoted, respectively, as alpha, delta, epsilon, gamma, and mu chains.


helical cone beam computed tomography

See spiral cone beam computed tomography.

Project: H59


HELLP syndrome

a group of symptoms in pregnant women including hemolysis, elevated liver enzymes, and low platelets (HELLP)

Project: NBS03

NOTE: The syndrome occurs in about 10% of pregnant women with preeclampsia or eclampsia.


helminth

may refer to a nematode (roundworm), cestode (tapeworm), or trematode (fluke)

Project: M28


hemadsorption

(Had) adherence of certain red blood cells to the surface of monolayered cells;

Project: m41

NOTE: HAd is mediated by expression of viral hemagglutinin proteins on the surface of cells infected by certain viruses (e.g., influenza) and can occur in the absence of CPE


hemagglutination

in viral culture, the clumping of certain red blood cells that can be observed in culture supernatants containing hemagglutinin proteins shed by cells infected by certain viruses (e.g., influenza)

Project: M41


hemagglutination

1) the clumping of red blood cells; 2) agglutination reactions using erythrocytes. (Cf. DI1)


hematocrit

the measure of the ratio of the volume occupied by the red blood cells to the volume of whole blood, expressed as a fraction or percentage

Project: POCT17, POCT13


hematocrit effect

(Hct effect) the influence of hematocrit on the ability for the device to obtain an accurate result.

Project: POCT07


hematoma

localized collection of blood, usually clotted, in an organ, space, or tissue, usually due to a break in the wall of a blood vessel (Dorland's Illustrated Medical Dictionary. 32nd ed. Elsevier Saunders; 2012)

Project: GP41


hematopoietic cell transplantation

(HCT) a term adopted by the Primary Immune Deficiency Transplant Consortium that refers to the intravenous infusion of hematopoietic cells collected from bone marrow, peripheral blood, or umbilical cord blood of a living related or unrelated donor to reconstitute hematopoietic function in patients with damaged or defective bone marrow or immune systems;

Project: NBS06

NOTE 1: Alternatively referred to as a “hematopoietic stem cell transplant”; NOTE 2: Peripheral blood cells collected for transplant are enriched through positive selection to increase the relative proportion of potential pluripotent stem cells capable of developing into normal hematopoietic (blood) cells; NOTE 3: HCT is a recommended treatment for severe combined immunodeficiency and many other primary immunodeficiencies.


hemiglobin

(Hi) hemoglobin in which the iron atoms have been oxidized to the ferric state and which has then been bonded with cyanide ions.

Project: H15


hemiglobincyanide

(HiCN) hemoglobin in which the iron atoms have been oxidized to the ferric state and which has then been bonded with cyanide ions.

Project: H15


hemizygous

describes an individual who has only one member of a chromosome pair or chromosome segment rather than the usual two; refers in particular to X-linked genes in males who, under usual circumstances, have only one X chromosome or individuals who have a deletion at corresponding loci on one of the homologous chromosomes (MM17).

Project: MM17


hemodialysis

a procedure used to remove toxic substances from blood in patients with severe renal failure.

Project: POCT14


hemoglobin

the iron-containing red pigment-protein of erythrocytes;

Project: POCT11

NOTE: Hemoglobin occurs most commonly with the iron in the ferrous (II) state in two forms: deoxygenated (deoxyhemoglobin, HHb) and oxygenated (oxyhemoglobin, O2Hb), which work in concert to transport oxygen to and from the tissues.


hemoglobin A1c

hemoglobin that is irreversibly glycated at one or both N-terminal valines of the beta-chains and is a major component of glycohemoglobin.

Project: C44


hemoglobin derivatives

a hemoglobin type characterized by the heme-iron portion of the molecule (Cf. C25).

Project: C25


hemoglobin oxygen saturation

(sO2) the amount of oxyhemoglobin in blood expressed as a (percent) fraction of the total amount of hemoglobin able to bind oxygen (ie, oxyhemoglobin plus deoxyhemoglobin) (C46).

Project: C46


hemoglobin variant

a hemoglobin type is characterized by the protein moiety of the molecule;

Project: NRSCL08

NOTE: Most specifically by the difference from hemoglobin A1. (Cf. C25)


hemoglobinometer

a photometer whose measurement scale has been calibrated directly in units of hemoglobin concentration.

Project: H15


hemoglobin-oxygen binding capacity

the maximum amount of oxygen that can be carried by the hemoglobin in a given quantity of blood;

Project: NRSCL08

NOTE: This is represented by: BO2 = [ctHb - (cdysHb)] · bO2, where bO2 = 1.39 mL/g and cdysHb is the concentration of dysfunctional or inactive hemoglobin. (Cf. C25)


hemoglobins

all those hemoglobin derivatives normally present in circulating blood. They include deoxyhemoglobin (HHb), oxyhemoglobin (O2Hb), carboxyhemoglobin (COHb), and hemiglobin [Hi; methemoglobin (metHb)]. Please see the current edition of CLSI/NCCLS document C46—Blood Gas and pH Analysis and Related Measurements for more detailed information.

Project: H15


hemolysate

the product that results from the lysis of whole blood (Cf. H9);

Project: H09

NOTE: See also erythrolysate.


hemolysis

the breakdown of red blood cells in serum or plasma, which frees the hemoglobin from the cells and creates a reddish tinge

Project: POCT04

NOTE: Hemolysis interferes with some laboratory tests.


hemolysis

the breaking down of red blood cells with liberation of hemoglobin (RHUD-1.7CD)

Project: C37


hemolysis

the breakdown of erythrocytes in blood, which frees the hemoglobin and intracellular contents from the cells;

Project: C56

NOTE: Serum or plasma prepared from hemolyzed blood has visible red color when released hemoglobin exceeds 200 mg/L (20 mg/dL). The serum or plasma concentrations of other abundant red cell components such as potassium, phosphate, and lactate dehydrogenase also may be increased.


hemothorax

as a subtype of pleural fluid, blood in the pleural space due to direct hemorrhage from an interrupted blood vessel.

Project: C49


heparin

a polysaccharide characterized by its anticoagulant properties (NRSCL8);

Project: NRSCL08, H47

NOTE: There are a variety of heparin "types," which have different affects on the APTT and PT coagulation tests. Unfractionated heparin (UFH) is a class of IV drugs that indirectly (through antithrombin) inhibit the enzymes thrombin and to some extent, factor Xa. The APTT is proportionately prolonged in the presence of UFH. Low molecular weight heparin (LMWH) is a class of heparin drugs consisting of smaller, more uniform-sized heparin molecules that inhibit mainly factor Xa, and minimally, and not in a dose-dependent manner, affect the APTT. Pentasaccharide is a heparin analog of five heparin subunits that inhibits factor Xa and only marginally affects the APTT.


heparin

(unfractionated) a mixture of complex glycosaminoglycans (mucopolysaccharides) of widely varying molecular weight (5000 to 50 000 d) derived from animal tissues, used for prevention and treatment of venous and arterial thrombosis.

Project: POCT14


heparinized

specimens anticoagulated with a heparin salt(s). (Cf. C29)

Project: C29


hertz

the derived standardized international (SI) units of inductance, defined as the frequency of one cycle per second, having units of S-1 (reciprocal seconds)

Project: GP28


heterocytotropic

that which attaches to other kinds of cells (Cf. DI1)

Project: DI01


heteroduplex analysis

electrophoretic technique in which the DNA to be analyzed is first heated and allowed to cool slowly to allow base pairing among the DNA fragments present;

Project: MM05

NOTE: These annealed products are separated by nondenaturing gel electrophoresis, in which fragments will be separated by both size and DNA sequence composition.


heterogeneic

with a different genetic constitution.

Project: DI01


heterogeneous immunoassay

an immunoassay that requires the physical separation of free labeled antigen (or antibody) from the labeled antigen (or antibody) bound in an immune complex before measurement of the quantity of label (Cf. I/LA15, DI1).

Project: DI01, I/LA23


heterogeneous immunoassay

an immunoassay that requires one or more steps to separate the bound from the free indicator.

Project: H59


heterologous

derived from another species (Cf. DI1)

Project: DI01


heterologous interpolation

a calibration scheme in which the standard or reference (calibration) dose-response curve is constructed using reagents that have a different (heterologous) specificity from those being used to measure the analyte of interest;

Project: I/LA20, ILA34

NOTE 1: This assay involves the performance of two (or more) simultaneously performed assays with different sets of reagents. The first is the calibration portion of the assay that can be illustrated by a total serum IgE standard (calibration) curve. The second portion of the assay involves the measurement of IgE antibody to a defined allergen specificity (eg, Ambrosia artemisiifolia, common/short ragweed). Once the analyte (IgE) is bound in both the calibration and antibody detection sections of the assay, the same conjugated, antihuman IgE detection reagent is added to both. The response results (counts per minute [CPM]-bound, optical density, fluorescence signal units) generated in the IgE anti-short ragweed portion of the assay are interpolated from the (heterologous) total serum IgE calibration curve in international units per milliliter (IUA/mL) or mass units per milliliter (ng/mL) of IgE, which are calibrated back to an IgE primary reference standard. Parallelism between the heterologous calibration curve and dose-response curve of test specimens analyzed at multiple dilutions is a requirement for the successful use of the heterologous interpolation calibration scheme; NOTE 2: Parallelism between the heterologous calibration curve and dose-response curve of test specimens analyzed at multiple dilutions is a requirement for the successful use of the heterologous interpolation calibration scheme.


heterophil

term applied to antigens that occur in more than one species of animal and that may be immunologically related to antigens also found in plants or microbes (Cf. DI1)

Project: DI01


heterophile antibodies

antibodies produced against poorly defined antigens that react with immunoglobulins from two or more species.

Project: ILA30


heterophile antibody

antibody produced against poorly defined antigens that react with immunoglobulins from two or more species, or exhibit rheumatoid factor activity and bind to the Fc portion of human or animal immunoglobulins.

Project: H59


heterophilic antibodies

antibodies in test sera that can bind to immunoglobulins from other species (eg, human antimouse immunoglobulins);

NOTE: The observed reactivity may be specific, as seen with sera from animal handlers or subjects that have received a therapeutic monoclonal antibody drug or immune serum, or nonspecific as a result of human autoantibody cross-reactivity (eg, rheumatoid factor). In either case, these heterophile antibodies can induce false-positive or false-negative clinical test results depending on the assay design.


heterophilic antibody

an antibody that has an affinity for an antigen other than its specific antigen.


heteroscedasticity

changes in the variability of a measurement procedure due to changes in the measurand level;

Project: EP14

NOTE: For example, when the standard deviation is significantly greater at the high end versus the low end of a measuring interval.


heterospecificity

describes an antiserum with reactivity against a variety of antigens

Project: NRSCL08


heterotropic

characteristic of tissues grafted into a site that is anatomically different from its site in the donor (Cf. DI1)

Project: DI01


heterozygosity

the presence of two different genotypes (single nucleotide polymorphisms) at a locus.

Project: MM21


heterozygous

having the two genes at corresponding loci on homologous chromosomes different for one or more loci (MM17).

Project: MM17


heterozygous

two genes at corresponding loci on homologous chromosomes having different nucleic acid sequences.

Project: MM19


Hgb

See hemoglobin.


HHS

abbreviation for the (US) Department of Health and Human Services, or its designee (US CFR 493 February 28, 1992)


high-complexity testing

laboratory tests in which the risk of erroneous results is high due to complicated reagent preparation, complex equipment, complicated troubleshooting, and maintenance;

Project: MM19

NOTE: Test performance and interpretation of results requires extensive knowledge of factors that could influence test results.


high-density storage system

storage shelving that is stacked together in several rows with one or two aisles

Project: QMS04

NOTE: Units are moved to create access aisles as needed.


high-efficiency particulate air filter

(HEPA) used to remove from the air 99.97% of particulates having a diameter of 0.3 μm

Project: QMS04


high-level protocol

a protocol describing the content of messages passed between systems.

Project: AUTO01, AUTO02, AUTO03


high-performance liquid chromatography

an analytical technique for performing chromatographic separations of organic compounds in which the eluent, or carrier, is a liquid under pressure (Cf. C3)


HIPAA

the acronym for the Health Insurance Portability and Accountability Act of 1996;

NOTE: The Administrative Simplification provisions of the Health Insurance Portability and Accountability Act of 1996 (HIPAA, Title II) require the Department of Health and Human Services to establish national standards for electronic healthcare transactions and national identifiers for providers, health plans, and employers. It also addresses the security and privacy of health data.


HIS

the computer system used for management of data collected and generated by various services, laboratories, and facilities served by a hospital.

Project: AUTO01


HIS

(hospital information system) the computer system used for management of data collected and generated by various services, laboratories, and facilities served by a hospital.

Project: AUTO10


HIS

abbreviation for Hospital Information System.

Project: AUTO02, AUTO03


HISB

abbreviation for Healthcare Informatics Standards Board.

Project: AUTO02


histogram

a graph of a frequency distribution in which rectangles on the horizontal or x-axis are given widths proportional to the intervals of the quantities being displayed, and heights proportional to the frequency of occurrence of quantities within that interval

Project: NRSCL08


histogram

see single-parameter display.

Project: H52


histogram channel number

the ordinal number beginning at zero that represents the relative position of a particular bin in a histogram;

Project: I/LA24

NOTE: When analog signals are digitized, the histogram channel number represents the relative strength of the original analog signal.


histomorphology

the cellular and architectural (eg, stromal, epithelial) features of a tissue;

Project: I/LA28

NOTE: As used in immunohistochemistry, it is the cell-type localization of the antibody-antigen reaction.


hit rate

proportion of the number of measurement results deemed to indicate presence of a measurand (positive detection result) to the total number of measurement results obtained.

Project: EP17


HITSP

abbreviation for Healthcare Information Technology Standards Panel.

Project: AUTO03


HIV seroreversion

reversal of a confirmed HIV serological test result from positive to negative (loss of detectable antibody).

Project: M53


HL7

abbreviation for Health Level Seven.

Project: AUTO01, AUTO02, AUTO03


homebrew assay

in the United States, a term that refers to an in vitro diagnostic that is a laboratory-developed test using separately purchased reagents that are not assembled in a kit and are without instructions for use from the manufacturer of the reagents;

Project: I/LA28

NOTE: The analytical and clinical performance characteristics of the finished assay are the responsibility of the laboratory director.


homeostasis

state of equilibrium of the internal body

Project: GP48


homo

a combining form that denotes “like” (Cf. DI1)

Project: DI01


homocytotropic

characteristic of antibodies that attach specifically to certain kinds of cells in the same species as that in which they are made (Cf. DI1)

Project: DI01


homogeneity

the condition of being of uniform structure or composition with respect to one or more specified properties.

Project: C37, C53


homogeneous

simultaneous amplification of the target and detection of the product in which data collection occurs throughout the process

Project: MM06


homogeneous immunoassay

an immunoassay in which no separation step is performed; an immunoassay that requires only the mixing of a sample (analyte) and immunochemical reagents (antibodies or antibody conjugates) with no wash step(s) to disturb the binding equilibrium before the bound fraction is measured;

Project: I/LA23

NOTE: The measurand (analyte) must produce a detectable dose-response signal upon binding that distinguishes it from unbound analyte.


homogeneous immunoassay

an immunoassay that does not require a step for the separation of the bound and free indicator.

Project: H59


homogeneous polymerase chain reaction

polymerase chain reaction (PCR) and amplicon detection performed in a single tube without an intervening separation or wash step;

Project: MM01

NOTE: Detection can be performed with specific reagents, such as molecular beacons. This is in contrast to heterogeneous PCR, in which the PCR amplicons are separated from amplification reagents before detection, usually by electrophoresis.


homogeneous, kinetic polymerase chain reaction

see real-time polymerase chain reaction.

Project: MM22, MM03


homogenization

the process by which high-molecular-weight gDNA and other high-molecular-weight cellular components are sheared to create a homogenous lysate; it is necessary to reduce the viscosity of the cell lysates created by disruption prior to final isolation;

Project: MM13

NOTE: Incomplete homogenization results in inefficient binding of DNA and/or RNA and therefore significantly reduced yields during purification.


homogenize

to reduce a patient sample to a small, uniform size dispersed in a liquid.

Project: M54


homologous

derived from an animal of the same species (Cf. DI1)

Project: DI01


homologous interpolation

a calibration scheme in which the standard or reference (calibration) dose-response curve is constructed using reagents that have the same (homologous) specificity from those being used to measure the analyte of interest;

Project: I/LA20, ILA34

NOTE 1: In this assay, both the calibrator and test specimens are analyzed using the identical assay reagents; NOTE 2: In an assay that measures ragweed-specific IgE antibody, for instance, the calibration curve is constructed with multiple dilutions of a serum containing a predefined amount of ragweed-specific IgE antibody. Test sera are simultaneously analyzed using the same reagents for IgE antiragweed. When complete, the response results (CPM-bound, absorbance, fluorescence signal units) generated for the test sera are interpolated from the IgE antishort ragweed calibration curve that has been precalibrated in arbitrary units or mass units per volume (eg, ng/mL). Depletion analysis, with or without elution, can be used to prepare an IgE antibody reference serum that has an assigned mass/volume quantity of allergen-specific IgE antibody; NOTE 3: Homologous interpolation is the conventional calibration scheme used by most clinical immunoassays; however, it has been rarely applied to IgE antibody assays, because large amounts of serum-containing IgE antibodies of all clinically relevant specificities are difficult to prepare. Moreover, because epitope specificities are rarely defined and they may differ with respect to the reference and test sera, homologous interpolation within the context of IgE assays is impractical.


homozygous

having the two genes at corresponding loci on homologous chromosomes identical for one or more loci (MM17).

Project: MM17, MM19


horizontal exit

route used to escape a fire that moves in a horizontal direction, such as a direct route to the outside or into another building through a fire-rated wall


hospital disinfectant

a US Environmental Protection Agency-registered agent with demonstrated effectiveness against Staphylococcus aureus, Salmonella choleraesuis, and Pseudomonas aeruginosa and may also be effective against specifically named organisms such as Mycobacterium tuberculosis, pathogenic fungi, or certain viruses.

Project: M29


hospital information system

(HIS) a data management system that usually supports functions external to the laboratory, eg, admission, discharge, and transfer (ADT) functions.

Project: AUTO02, AUTO03


hospital information system

(HIS) the computer system used to manage data collected and generated by various services, laboratories, and facilities served by a hospital/health care system (M39).

Project: ILA33, POCT07


hospital/health care information system

the computer system used to manage data collected and generated by various services, laboratories, and facilities served by a hospital/health care system.

Project: M39


hot zone

the site of an overt incident of any type.


housekeeping proteins

proteins that are constitutively expressed under all physiological conditions and are important for maintaining basic cellular function

Project: M58


human factors engineering

interdisciplinary approach for evaluating and improving the safety, efficiency, and robustness of work systems;

Project: QMS11

NOTE: Human factors engineering addresses multiple aspects of work, including task analysis and design; device evaluation and usability; communication, collaboration, and teamwork; training; and systems resilience, adaptation, and failure.


human papillomavirus

(HPV) the most common sexually transmitted virus and causative agent in the pathogenesis of cervical cancer and its precursor lesions in almost all cases.

Project: GP15


humoral immunity

immune responses that involve secretion of specific antibodies produced by B-cells.

Project: NBS06


hybrid

anything derived from heterogeneous sources, or composed of heterogeneous elements

Project: NRSCL08


hybridization

a base pairing of complementary strands of nucleic acid by hydrogen bond formation; the binding of probe to specific nucleic acid sequences or amplification products (NRSCL8);

Project: NRSCL08, MM10, MM12, MM01

NOTE 1: Hybridization can be performed with both nucleic acid target and probe in solution, or with the nucleic acid target retained within a tissue specimen; this latter form of hybridization is referred to as “in situ hybridization” (Cf. MM04); NOTE 2: Hybridization can be performed with both nucleic acid target and probe in solution, with nucleic acid target attached to a solid support, or with either one bound to a solid support such as a microtiter plate or membrane; NOTE 3: Hybridization can be performed with both nucleic acid target and probe in solution, or with either one bound to a solid support such as a microtiter plate, glass, or membrane.


hybridization

a base pairing of complementary strands of nucleic acid by hydrogen bond formation; the binding of probe to specific nucleic acid sequences or amplification products;

Project: MM22, MM09

NOTE: Hybridization can be performed with both nucleic acid target and probe in solution, or with either one bound to a solid support such as a microtiter plate, glass, or membrane.


hybridization

a base pairing of complementary strands of nucleic acid by hydrogen bond formation; the binding of probe to specific nucleic acid sequences or polymerase chain reaction amplification products;

Project: I/LA28

NOTE: Hybridization can be performed with both nucleic acid target and probe in solution, or with the nucleic acid target retained within a tissue specimen. This latter form of hybridization is referred to as “in situ hybridization.”


hybridoma

a cell made in the laboratory by fusing a normal cell with a cancer cell to combine certain features of each;

Project: NRSCL08

NOTE: Most specifically, a cell line derived by the fusion of a B cell and a plasmacytoma cell, usually for the production of monoclonal antibodies. (Cf. I/LA18)


hydrolysis probe

in real-time polymerase chain reaction (PCR), during the primer extension step, Thermus aquaticus polymerase with a 5´–3´ exonuclease activity cleaves a fluor/quencher-labeled probe hybridized to the complementary target sequence. As in other real-time PCR methods, the resulting fluorescence signal permits quantitative measurements of the accumulation of the product during the exponential stages of the PCR.

Project: MM19


hyperacute rejection

a severe, nonreversible rejection of transplanted tissue that is mediated by preformed antibody response.

Project: ILA29


hyperglycemia

high blood glucose (BG) levels or BG higher than the target range for the patient;

Project: POCT13

NOTE: BG may be considered “high” at various glucose concentrations, eg, greater than 140 mg/dL (7.8 mmol/L), 160 mg/dL (8.9 mmol/L), or 180 mg/dL (10 mmol/L), for different clinical settings in different publications.


hyperglycemia threshold

the glucose level that is considered to be high as determined by the clinician, and that must be detected at a stated sensitivity for a device to be considered effective (POCT05);

Project: POCT05

NOTE: The hyperglycemia threshold may be the same as or higher than the alarm threshold for hyperglycemia (POCT05).


hyperglycemic event

an instance or instances in which the glucose level is at or above the hyperglycemia threshold (POCT05);

Project: POCT05

NOTE: Multiple glucose levels above the hyperglycemic threshold during this interval are considered to be a single hyperglycemic event (POCT05).


hypersensitivity reactions

undesirable (ie, damaging, discomfort-producing, and sometimes fatal) reactions produced by the normal immune system. Hypersensitivity reactions require a presensitized (immune) state of the host.

Project: MM19


Hypertext Transfer Protocol

(HTTP) a TCP-based, application-layer, client-server, Internet protocol used to carry data requests and responses in the World Wide Web. (RFC 2828)

Project: AUTO09


hypertrypsinogenemia

an elevated level of trypsinogen in blood specimens, as in the dried blood spots obtained from newborns

Project: NBS05

NOTE: The meaning of “elevated” varies depending on the immunoreactive trypsinogen method used and the cutoff value selected.


hypha

(pl. hyphae) a septate or aseptate filament of a fungus.

Project: M54


hypoglycemia

an abnormally low level of glucose in the blood (eg, blood glucose concentration below 70 mg/dL [3.9 mmol/L])

Project: POCT17, POCT13


hypoglycemia threshold

the glucose level that is considered to be low as determined by the clinician and that must be detected at a stated sensitivity for a device to be considered effective (POCT05);

Project: POCT05

NOTE: The hypoglycemia threshold may be the same as or lower than the alarm threshold for hypoglycemia (POCT05).


hypoglycemic event

an instance or instances in which the glucose level is at or below the hypoglycemia threshold (POCT05);

Project: POCT05

NOTE: Multiple glucose levels below the hypoglycemic threshold during this interval are considered to be a single hypoglycemic event (POCT05).


hypothesis

1) in a trial, a statement relating to the possible different effect of the interventions on an outcome; 2) a supposition, arrived at from observation or reflection, that leads to refutable predictions

Project: GP45

NOTE 1: The null hypothesis of no such effect is amenable to explicit statistical evaluation by a hypothesis test, which generates a P-value.


hypothesis testing

in Statistics, the testing of two or more statistical hypotheses that are mutually exclusive so that exactly one hypothesis can be accepted at a specified confidence level.


hypothesis testing

in Statistics, the testing of two or more statistical hypotheses that are mutually exclusive so that exactly one hypothesis can be accepted at a specified confidence level.

Project: NRSCL08


iatrogenic anemia

anemia caused by diagnostic blood sampling

Project: GP41, GP48


IC50

concentration of antiviral agent that inhibits virus production by 50% as measured, for example, by plaque formation, DNA synthesis, or antigen-production;

Project: M33

NOTE: Antiviral susceptibility results have been traditionally expressed as IC50 values.


icterus

serum with yellow color resulting from elevated bilirubin in the blood;

Project: C37

NOTE 1: Typically due to an increase of bile pigments in the blood, especially bilirubin, and often symptomatic of certain diseases, such as hepatitis; NOTE 2: A sample from a patient with icterus can produce erroneous test results due to either direct optical interference or chemical interference or both.


icterus

a yellow color resulting from an increased concentration of bilirubin.

Project: C56


identification

the process of establishing a claim to be a particular user; NOTE: Identification normally involves supplying a user ID, radio frequency ID badge, or bar-coded badge without password, etc.

Project: AUTO11


identity

the extent to which two (nucleotide or amino acid) sequences are invariant (MM18).

Project: MM18


idiospecificity

a characteristic that describes the reactivity of an antiserum with a unique subset of a broad antigen class. (Cf. DI1)

Project: DI01, I/LA23


idiotype

the characteristic of an antigen that makes it unique among all others of the same isotype;

Project: NRSCL08

NOTE: The term is usually applied to a monoclonal immunoglobulin, and the idiotypic characteristic has been shown to be located in the F(ab) combining site. (Cf. DI1)


IEEE

abbreviation for Institute of Electrical and Electronics Engineers, Inc.

Project: AUTO01, AUTO02, AUTO07, AUTO03


IEEE 1073

a family of standards for medical device communications that are optimized for the acute care setting;

Project: POCT02, POCT01

NOTE 1: Devices include patient monitors, ventilators, infusions pumps, pulse oximeters, etc.; standards include IEEE Standard 1073 and lower-layers IEEE Standard 1073.3.2; also referred to as “MIB” (see Medical Information Bus); NOTE 2: These are internationally harmonized as the ISO/IEEE 11073 set of standards.


IFCC

abbreviation for International Federation of Clinical Chemistry and Laboratory Medicine.

Project: AUTO01, AUTO02, AUTO03


ignitable

a substance that, under standard temperature and pressure, is capable of causing fire through friction, absorption of moisture, or other spontaneous chemical change and that, when ignited, will burn vigorously and persistently.

Project: GP05


illuminate

as used in I/LA24, to supply a measurand with a source of light for purposes of exciting fluorochrome molecules with which the measurand may be labeled;

Project: I/LA24

NOTE 1: Fluorochrome molecules in the measurand are illuminated by incident light from the fluorometer; NOTE 2: These terms are often used interchangeably with the terms "excite/excitation." However, illumination is predetermined by instrument conditions alone, whereas excitation depends further on fluorochrome and environmental factors.


image cytometer

any of a group of instruments comprising fluorescence microscopes and microphotometers, image and scanning cytometers, and confocal microscopes that illuminate and collect optical signals from a microscopic field;

Project: I/LA24

NOTE: Image cytometers generally use microscope objectives (lenses with relatively high numerical aperture [N.A.] and magnification) to maximize illumination and detection efficiency.


immature reticulocyte fraction

a quantitative expression of the maturation state of the entire reticulocyte population in the peripheral blood;

Project: H44

NOTE 1: This has been expressed in terms of mean fluorescence intensity using thiazole orange on multiparameter flow cytometry instruments and as a fractional expression of the subpopulation of the reticulocytes having the highest fluorescence RNA intensity or RNA content; NOTE 2: Previously called reticulocyte maturation index.


immature reticulocyte fraction

a quantitative expression of the maturation state of the entire reticulocyte population in the peripheral blood;

Project: H44

NOTE 1: This has been expressed in terms of mean fluorescence intensity using thiazole orange on multiparameter flow cytometry instruments and as a fractional expression of the subpopulation of the reticulocytes having the highest fluorescence RNA intensity or RNA content; NOTE 2: Previously called Reticulocyte maturation index.


immediate action

act or deed performed without hesitation upon recognition or awareness of a nonconforming event;

Project: QMS11

NOTE: The action should be documented.


immediate container

packaging that protects the contents from contamination and other effects of the external environment (ISO 18113-1)

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3

EXAMPLES: Sealed vial, ampoule or bottle, foil pouch, sealed plastic bag (ISO 18113-1); NOTE: Does not include package liners (ISO 18113-1).


immersion oil

liquid medium, occupying the space between the object and microscope objective, used to optimize the resolution of the image being magnified.

Project: HS02, POCT10


immune assay

See immunoassay.


immune complex

a complex formed of antigen and specific antibody molecules;

Project: NRSCL08, ILA29

NOTE: May also include complement components and other molecules as well.


immune threshold

the minimal level of specific antibody required for the protection of a person against an infectious agent. (Cf. I/LA18)

Project: I/LA18


immunoassay

any laboratory method for detecting a substance by using an antibody (pair) that is reactive with or binding to the test analyte or substance of interest

Project: I/LA20

NOTE: Immunoassays can be competitive or noncompetitive, solid or liquid phase, isotopic or nonisotopic, labeled antigen or immunometric (labeled antibody), single or dual site, homogeneous (no separation step), heterogeneous (separation step), or manual or automated with robotic autoanalyzers. The majority of clinically used total immunoglobulin E (IgE) and allergen-specific IgE assays are noncompetitive heterogeneous immunometric assays.


immunoassay

a diagnostic test that uses a specific antibody or antigen to detect the presence of an analyte (POCT04).


immunoassay

a ligand-binding assay that uses a specific antigen or antibody capable of binding to the analyte (NRSCL8).

Project: C45, NRSCL8


immunoassay

any laboratory method for detecting a substance by using an antibody reactive with it (RHUD2CD).

Project: ILA34

NOTE: Immunoassays can be competitive or noncompetitive, solid or liquid phase, isotopic or nonisotopic, labeled antigen or immunometric (labeled antibody), single or dual site, homogeneous (no separation step), or heterogeneous (separation step). The majority of clinically used total IgE and allergen-specific IgE assays are noncompetitive heterogeneous immunometric assays.


immunoassay

an analytical procedure in which antibodies are used to detect or quantify the corresponding antigen;

Project: H59

NOTE: Immunoassays can be used to quantify D-dimer and some methods that may be employed are nonlabeled immunoassays/microparticle agglutination immunoassays, indicator-labeled immunoassays, and sandwich immunoassays.


immunoassay

any laboratory method for detecting an analyte using an antibody reactive with it;

Project: ILA28

NOTE: An immunoassay is a ligand-binding assay that uses a specific antigen or antibody capable of binding to the analyte.


immunoassay

a biochemical test that detects the presence of antigen or antibody in a biological specimen using the binding of an antibody to an antigen.

Project: M53


immunocytochemical assay

an immunoassay that detects an antigen present in a specimen that is contained within intact or histologically sectioned cells or tissues (MM04);

Project: MM04, H56, I/LA28

NOTE: Such an assay is also referred to as an immunohistochemical assay; the process that encompasses the preparation and examination of tissues stained in this way is variously referred to as immunocytochemistry, immunohistochemistry, immunohistology, or immunomicroscopy, among others.


immunocytology

localization of immunoreactive substances within cells of a cytological specimen that have been specifically labeled with an antibody.

Project: H56


immunodiffusion

an immunological method for measuring antigens (eg, serum proteins) in which a small amount of serum (eg, 5 μL) is pipetted into a well cut into a porous agarose gel

Project: I/LA20

NOTE 1: In the single immunodiffusion or Mancini assay, the gel contains antibody specific for the analyte of interest. As the analyte migrates through the gel by diffusion, it binds to antibody and forms a precipitin line at a point of optimal antigen-antibody binding or equivalence. In the double immunodiffusion assay, antigen and specific antibody are pipetted into separate wells in the same gel and they diffuse in all directions. A precipitin line forms at equivalence (the point of maximal antigen-antibody cross-linking). The shape and location of lines and diameter of precipitin rings provide information about the analyte’s quantity and quality; NOTE 2: Immunodiffusion is not used to measure IgE antibodies in serum because of its inadequate lower limit of detection. Rather, it can be used by allergen manufacturers to qualify allergen extracts as part of a quality assurance program.It is also used in clinical immunology laboratories to evaluate patients suspected of having hypersensitivity pneumonitis who frequently have precipitins (precipitating antibodies) in their blood.


immunogen

any substance that elicits a cellular and/or humoral immune response and the production of antibody in a biological system.

Project: ILA18, ILA23, ILA34


immunogenicity

the ability of a biomolecule to elicit an antibody response.

Project: ILA34


immunoglobulin

(Ig) any of several classes of structurally related glycoproteins that function as antibodies or receptors and are found in plasma, other body fluids, and in the membranes of certain cells (DI01).

Project: DI01, MM05, I/LA28


immunoglobulin

(Ig) a glycoprotein composed of two heavy and two light chains that functions as an antibody;

Project: I/LA20, ILA34, NBS06

NOTE: Human immunoglobulins have been subdivided into different classes or isotypes (IgM, IgG1, IgG2, IgG3, IgG4, IgA1, IgA2, IgD, IgE), each of which possesses a unique set of antigenic markers, physiochemical properties, and each of which produces a different pattern of effector functions (receptor binding, complement activation, opsonization). All antibodies are immunoglobulins, but it is not certain that all immunoglobulins possess antibody function.


immunoglobulin class

a classification of immunoglobins based on antigenic and structural differences of the heavy (H) chain;

Project: NRSCL8

NOTE: There are five classes: IgG, IgA, IgM, IgD, and IgE. (Cf. DI1, H42)


immunoglobulin class

a classification of immunoglobins based on antigenic and structural differences of the heavy (H) chain;

Project: MM05, M36

NOTE: There are five immunoglobulin classes: IgG, IgA, IgM, IgD, and IgE.


immunoglobulin E

human IgE is an immunoglobulin of the approximate molecular weight of 190 000, which exists normally in monomeric form and constitutes approximately 0.0005% of the total serum immunoglobulins

Project: I/LA20, ILA34

NOTE: It binds with high affinity to FcεR1 (fragment crystallisable-epsilon receptor 1)  mainly expressed on mast cells and basophils and FcεR2 receptors on a number of other cells. IgE mediates the production and release of vasoactive mediators following the binding of allergen.


immunoglobulin fragment

a variable region of the IgG immunoglobulin molecule containing an antibody-combining site;

Project: NRSCL08

NOTE 1: Obtained by treating the molecule with the enzyme papain, specific fragments include: (i) F(ab) Fragment - the fragment consisting of a single antibody-combining site, embodied in an intact light chain and the F(d) fragment of one heavy chain, held together by means of a disulfide bond; (ii) F(ab') Fragment - the fragment obtained after papain treatment and reduction, and consisting of an intact light chain and the F(d') fragment of one heavy chain, held together by means of a disulfide bond; (iii)F(ab')2 Fragment - the fragment obtained after papain treatment without subsequent reduction and consisting of a dimer of two F(ab') fragments held together by two disulfide bonds; (iv) F(c) Fragment - the crystallizable fragment containing the complement and rheumatoid factor-binding regions and consisting of two heavy chain fragments joined by two disulfide bonds; (v) F(d) Fragment - the fragment obtained after papain treatment and reduction, and consisting of that portion of the heavy chain joined to an intact light chain in the F(ab) fragment; (vi) F(d') Fragment - the fragment obtained after papain treatment and reduction, and consisting of that portion of the heavy chain that is joined to an intact light chain in the F(ab') fragment (Cf. DI1, I/LA18).


immunoglobulin isotype

See immunoglobulin class.

Project: MM05


immunoglobulin subclass

a subdivision of immunoglobulin classes based on structural and antigenic differences in the H chain;

Project: NRSCL08

NOTE: For humans, there are four IgG subclasses: IgG1, IgG2, IgG3, and IgG4. For IgA, there are two subclasses: IgA1 and IgA2; IgM subclasses have been postulated; IgD and IgE subclasses are unknown. (Cf. DI1)


immunohematology

(IH) the study of antigen-antibody reactions as they relate to transfusion medicine.

Project: ILA33


immunohistochemical

of or relating to the application of histochemical and immunologic methods to chemical analysis of living cells and tissues (MM17).

Project: MM17


immunohistochemical assay

an immunoassay that detects an antigen present in a specimen that is contained within intact or histologically sectioned tissue;

Project: I/LA28

NOTE: Such an assay is also referred to as an “immunocytochemical assay”; the process that encompasses the preparation and examination of tissues stained in this way is variously referred to as “immunocytochemistry,” “immunohistochemistry,” “immunohistology,” or “immunomicroscopy,” among others.


immunohistology

localization of immunoreactive substances within cells or tissues of a histological specimen that have been specifically labeled with an antibody.

Project: H56


immunophenotyping

characterization of cells by the identification of cell surface or intracellular antigens, utilizing antibody reagents that recognize specific cell associated molecules (H42, H43);

Project: H42, H43

NOTE: In this guideline, the cells that are immunophenotyped are lymphocytes and hematopoietic stem and progenitor cells (H42, H43); NOTE: In H52, the cells that are immunophenotyped are RBCs and WBCs.


immunophenotyping

characterization of cells by the identification of cell-surface or intracellular antigens, using antibody reagents that recognize specific cell-associated molecules;

Project: H52

NOTE: In H52, the cells that are immunophenotyped are RBCs and WBCs.


immunoprecipitation

the separation of an antigen from a solution by the formation of a large insoluble complex with its specific antibody

Project: NRSCL08


immunoprecipitin analysis

an immunoassay that relies on formation of a precipitate of antibody and antigen (Cf. I/LA15)


immunoreactive trypsinogen

one of the secretory products of the pancreas, thus facilitating the use of its level in blood as a specific marker for pancreatic function

Project: NBS05

NOTE: The acinar cells of the pancreas secrete two major forms of enzymatically inactive trypsinogen, which are subsequently activated to trypsin upon cleavage of a hexapeptide from the N-terminus.


immunoreactivity

See reactivity.

Project: I/LA28


impedance

the total electrical resistance measured between two electrodes (H58).

Project: H58


impedance aggregometry

an in vitro platelet aggregation assay, primarily done in whole blood or diluted whole blood that measures the change in resistance between two electrodes caused by platelet clumping following activation of platelets by agonists (CLSI document H58).

Project: H58


implementation

putting into service, an instrument or method, by means of a definite plan or process (H57).

Project: H57


implementation

the act of accomplishing some aim, executing some order, or carrying into effect.

Project: ILA33


implementation plan

detailed listing of activities, costs, expected difficulties, and schedules that are required to achieve the objectives of the strategic plan.

Project: QMS13


importer

person/entity who imports a device into a country and furthers the marketing of a device from the original place of manufacture to the ultimate user ( ISO CD 18112-1)

Project: ISO CD 18112-1


importer

person or legal entity who brings goods, or causes goods to be brought into a country from another country (ISO 18113-1)

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3

NOTE 1: Importers are not permitted to repackage the goods or change their container, packaging or labelling in some jurisdictions, including the EU and USA (ISO 18113-1); NOTE 2: Adapted from US Code of Federal Regulations (CFR), Title 21, Part 803 — Medical Device Reporting Regulation 803.3 (m) (ISO 18113-1). 


imprecision

the random dispersion of a set of replicate measurements and/or values expressed quantitatively by a statistic, such as standard deviation or coefficient of variation

Project: C24, H20, C54, H26, EP23, EP27, EP09, EP26, EP05

NOTE 1: It is defined in terms of repeatability and reproducibility; NOTE 2: The words "imprecision" and “precision” are often inappropriately interchanged; NOTE 3: It is expressed numerically as standard deviation or coefficient of variation.

 


imprecision

the presence of random error, variability, or inconsistency

Project: POCT04


imprecision

for quantitative measurement procedures, dispersion of independent results of measurements obtained under specified conditions;

Project: EP19

NOTE: It is expressed numerically as the standard deviation (SD) or the coefficient of variation (SD divided by the mean measurement procedure result).


imprecision

dispersion of independent results of measurements obtained under specified conditions

Project: EP33, H48, MM10, POCT14, EP07, EP10, EP14, ILA23, C58, I/LA26, C48, H54, MM12, C49, EP12, H57, C34, MM06, H59, GP34, MM19, NBS05, MM01, C56, MM20, C40, MM22, H60, C62, C57, MM23, POCT13, POCT06

NOTE: It is expressed numerically as standard deviation or coefficient of variation.


imprecision

(uncertainty of measurement) parameter, associated with the result of measurement, that characterizes the dispersion of the values that could reasonably be attributed to the measurand (the quantity intended to be measured).

Project: POCT07


imprecision

scattering of independent results of measurements obtained under specified conditions;

Project: POCT05

NOTE: It is expressed numerically as standard deviation or coefficient of variation.


Improvement Management Program

an ongoing quality assessment and improvement process that establishes the most important monitoring targets to ensure the organization's ability to provide optimal customer satisfaction.


in cis

two mutations on the same parental gene; two mutations in one allele on one copy of the chromosome (chromosome 7, in the case of cystic fibrosis)

Project: NBS05


in control

characterization of a process when results from a control sample or a series of control samples are within the acceptable control range (Cf. POL1/2)

Project: POL1/2


in silico

an analysis performed on a computer or via computer simulation.

Project: MM22


in trans

two mutations on different parental genes

Project: NBS05

NOTE: Each of the mutations is in a different copy of the allele (eg, one on each chromosome 7, in the case of cystic fibrosis).


in vitro

a Latin term, meaning “in glass,” used to describe diagnostic tests that analyze processes or quantities that originate inside the body (in vivo) based on samples of body fluids or tissues in glass (test tubes) or other controlled, artificial environments. (Cf. POL1/2)

Project: POL1/2


in vitro diagnostic

(IVD) term used to describe those reagents, instruments, and systems intended for use in the diagnosis of disease or other conditions, including a determination of the state of health, in order to cure, mitigate, treat, or prevent disease or its sequelae. Such products are intended for use in the collection, preparation, and examination of specimens taken from the human body.

Project: NRSCL08


in vitro diagnostic device

term used to describe those reagents, instruments, and systems intended for use in the diagnosis of disease or other conditions, including a determination of the state of health, in order to cure, mitigate, treat, or prevent disease or its sequellae. Such products are intended for use in the collection, preparation, and examination of specimens taken from the human body.

Project: MM22


in vitro diagnostic device

in Europe, any medical device that is a reagent, reagent product, calibrator, control material, kit, instrument, apparatus, equipment, or system, whether used alone or in combination, intended by the manufacturer to be used in vitro for the examination of specimens, including blood and tissue donations, derived from the human body, solely or principally for the purpose of providing information (Directive 98/79/EC);

Project: MM19

NOTE 1: In the United States, the US Food and Drug Administration (FDA) defines IVD devices as those reagents, instruments, and systems intended for use in diagnosis of disease or other conditions, including a determination of the state of health, in order to cure, mitigate, treat, or prevent disease or its sequelae. Such products are intended for use in the collection, preparation, and examination of specimens taken from the human body; NOTE 2: In the United States, the FDA regulates IVD devices, and these are subject to premarket and postmarket controls.


in vitro diagnostic instrument

equipment or apparatus component of an in vitro diagnostic examination procedure that is used for detecting, measuring, controlling, or computing a quantity in a sample.

Project: AUTO11


in vitro diagnostic instrument

equipment or apparatus intended by a manufacturer to be used as an IVD medical device (ISO 18113-1)

Project: ISO 18113-1

NOTE: Adapted from EN 591:2001, definition 3.5 (ISO 18113-1).


in vitro diagnostic medical device

device, whether used alone or in combination, intended by the manufacturer for the in vitro examination of specimens derived from the human body solely or principally to provide information for diagnostic, monitoring, or compatibility purposes and including reagents, calibrators, control materials, specimen receptacles, software, and related instruments or apparatus or other articles (ISO 18113-1)

Project: ISO 18113-1, ISO/DIS 14971


in vitro diagnostic medical device

a harmonized definition of medical device, including in vitro diagnostic medical device, has been proposed by the Global Harmonization Task Force, but has not yet been adopted by the participating countries; the European union, the United States, and Canada consider calibrators and control materials to be IVD medical devices and must be labelled as such; in Japan, IVD regulations do not apply to calibrators and control materials, unless they are part of a kit; accessories are IVD medical devices, according to EU definition, only when they are specifically intended for diagnostic use by their manufacturer.

Project: ISO/TR 18112


in vitro diagnostic medical device

device for in vitro examination that includes, for example, reagents, calibrators, sample collection devices, control materials, and related instruments or apparatus, and that provides information that may be used for diagnostic, monitoring, or compatibility purposes;

Project: ISO CD 18113-1, ISO CD 18113-2, ISO CD 18113-3

NOTE: Taken from the Global Harmonization Task Force (GHTF) harmonized definition of medical device.


in vitro diagnostic medical device

a device, whether used alone or in combination, intended by the manufacturer for the in vitro examination of specimens derived from the human body solely to provide information for diagnostic, monitoring, or compatibility purposes and including reagents, calibrators, control materials, specimen receptacles, software, and related instruments or apparatus or other articles (GHTF/SG1/N045:2008).

Project: GP16, EP25, ISO 18113-1, H26, EP23


in vitro diagnostic mobile application

applications installed on mobile devices that allow in vitro device systems to be monitored and controlled.

Project: AUTO11


in vitro diagnostic reagent

in vitro diagnostic medical device which is a reagent, calibrator, control material, or kit containing the components of an IVD assay (ISO/CD 18112-1);

Project: ISO CD 18112-1

NOTE: For a harmonized definition of IVD medical device, see Global Harmonization Task Force (GHTF), Information Document Concerning the Definition of theTerm “Medical Device,” Proposed Final Document SG1/N029R13.


in vitro diagnostic reagent

chemical, biological, or immunological components, solutions, or preparations intended by the manufacturer to be used as an IVD medical device (ISO 18113-1)

Project: ISO 18113-1

NOTE: Adapted from EN 375:2001, definition 3.9 (ISO 18113-1). 


in vitro diagnostic reagent

chemical, biological, or immunological component, solution, or preparation intended by the manufacturer to be used as an IVD medical device (ISO 19001)

Project: ISO 19001


in vitro diagnostic reagent

chemical, biological, or immunological component of an in vitro diagnostic examination procedure that produces a signal by chemical or electrochemical reaction for the purpose of detecting or measuring a quantity in a sample (modified from ISO/DIS 17593)


in vitro diagnostic software system

a data management system for managing in vitro device testing in a health care organization.

Project: AUTO11


in vitro diagnostic system

an in vitro diagnostic instrument or in vitro diagnostic software system.

Project: AUTO11


in vitro diagnostic use

diagnostic product cleared or approved by a national regulatory body for one or more specific intended uses with established analytical and clinical performance characteristics


in vitro postantibiotic effect

(PAE) the difference in the time for the number of exposed vs nonexposed bacteria to exhibit 1 log increase in colony-forming units. It is measured after a short exposure of microorganisms to an antimicrobial, after which time the antimicrobial is removed. The exposure concentrations relative to the MIC should be indicated. In vitro PAE may vary as a function of the magnitude of drug concentrations to which the bacteria were exposed relative to the MIC of that microorganism.

Project: VET02


in vitro stimulation

(IVS) a term used to indicate that an activating agent has been added to cells (often peripheral blood mononuclear cells) in culture;

Project: I/LA26

NOTE 1: The purpose is often to induce the expression of new cell surface markers (eg, activation markers) or other target molecules (eg, intracellular cytokines) on or in cells; NOTE 2: IVS is a term also used to indicate that cells in culture have been induced to proliferation.


in vivo PAE

the difference in time for the number of bacteria in a tissue of treated vs untreated animals to exhibit a 1 log10 increase in colony forming units (CFUs) after the unbound drug concentrations in serum or the infection site fall below the MIC of the microorganism.

Project: VET02


inaccuracy

numerical difference between a value and the true value

Project: POCT04, LA01, MM10, EP07, MM12


inaccuracy

numerical difference between a measured value and the value of the measurand.

Project: C56, H60


inactive hemoglobin

See dyshemoglobin.


inactive leaf

door section that is normally fixed in a closed position unless manually unlatched to open

Project: QMS04


inadequate blood volume

a blood culture bottle containing less than 80% of the recommended minimum volume indicated on the bottle label.

Project: M47


incidence

an expression of the rate at which a certain event occurs, for example, the number of new cases of a specific disease occurring during a specific period

Project: NRSCL08, GP45, H59

NOTE 1: The number of instances of illness or other outcomes commencing, or of persons falling ill, during a given period in a specified population; NOTE 2: More generally, the number of new events, eg, new cases of a disease in a defined population, within a specified period of time.


incidence

rate at which new cases of a disease occur in a population in a specified period of time.

Project: M53


incident

an individual occurrence or event.


incident command system

a type of command structure specifically useful for management of emergency operations;

Project: GP36

NOTE 1: Incident command system implementation confers a standardized, scalable command and control structure that can include and coordinate diverse responders, such as public health authorities, medical workers, firefighters, and law enforcement personnel; NOTE 2: A useful, National Incident Management System–compliant resource for hospitals and health care is the Hospital Incident Command System (HICS), which adapts ICS specifically to a hospital environment. HICS is the property of the California Emergency Medical Services Authority.


incident light

as used in I/LA24, the light supplied by a fluorometer to illuminate a measurand for purposes of exciting fluorochrome molecules with which the measurand may be labeled.

Project: I/LA24


incision

a cut into the skin, using an automated skin puncture device, for the purpose of obtaining capillary blood

Project: GP42


incomplete agglutination

any agglutination reaction that does not proceed to an apparent agglutination;

Project: Dl01

NOTE: Caused by various conditions (e.g., antibody without free valency to participate in lattice formation, a prozone phenomenon, hypoviscosity of the assay medium, excessive distance between particles due to high ionic strength of the reaction mixture, which precludes antibody bridging).


incomplete anti-HIV antibody response

the failure to produce the full complement of anti-HIV antibodies required to meet the criteria for HIV infection by Western blot testing;

Project: M53

NOTE: This result is also known as an indeterminate Western blot result.


inconclusive result

as used in NBS06, a result from a newborn screening laboratory assay that cannot be classified as positive or negative.

Project: NBS06


inconclusive screening result

as used in NBS07, a result from a newborn screening laboratory assay that cannot be classified as positive or negative.

Project: NBS07


incorrect result

result that does not meet the requirements for its intended medical use;

Project: EP18, EP23

NOTE 1: In the case of quantitative test procedures, a result with a failure of measurement that exceeds a limit based on medical utility; NOTE 2: In the case of qualitative test procedures, a result that is contrary to a true value of the measurand.


independent laboratory

in GP36, a clinical laboratory that is not physically or directly associated with an acute care hospital; synonymous with “free standing” laboratory;

Project: GP36

NOTE: Independent laboratories do not inherit emergency preparedness assets that are available generally to many hospital laboratories, such as generator power, food services, security, medical expertise, behavioral health support, and facilities to house staff. They need to consider independently planning for these assets to meet their intended scopes of emergency operations.


independent test

a lupus anticoagulant test, screening or confirmatory, that is not paired with a test of the same principle;

Project: H60

NOTE: For example, the activated partial thromboplastin time is an independent screening test and the platelet neutralization procedure is an independent confirmatory test.


indeterminate

not definitely or precisely determined or fixed; not leading to a definite end or result.

Project: H60


indeterminate isolates

a microorganism of undetermined clinical importance.

Project: M47


indeterminate zone

term sometimes used instead of equivocal or gray zone, separating the “target absent” and “target present” zones (MM17);

Project: MM17

NOTE: In such assays, if the data generated by the assay fall within certain ranges, the data analysis may provide a result that is not definitive, such as neither “absent” nor “present” for a specific target, or neither “heterozygous” nor “homozygous” for a specific mutation site (MM17).


index

fixed or movable part of a displaying device whose position with reference to the scale marks enables an indicated value to be determined (VIM93) EXAMPLES a) pointer; b) luminous spot; c) liquid surface; d) recording pen


index of circulating anticoagulant

formula used to calculate a normalized ratio for a mixing test using either an independent or paired screening test; also referred to as the Rosner Index after the first author of the original publication.

Project: H60


index of individuality

the ratio of the combined within-subject biological variation (CVI) and the measurement procedure imprecision (analytical imprecision) (CVA) to the between-subject biological variation (CVG).

Project: EP33


index swapping

an incorrect association of a bar code due to read errors.

Project: MM09


indicating measuring instrument

measuring instrument providing an output signal carrying information about the value of the quantity being measured (JCGM 200:2008);

Project: ISO IEC Guide 99

EXAMPLES: Voltmeter, micrometer, thermometer, electronic balance (JCGM 200:2012); NOTE 1: An indicating measuring instrument may provide a record of its indication (JCGM 200:2012); NOTE 2: An output signal may be presented in visual or acoustic form. It may also be transmitted to one or more other devices (JCGM 200:2012).


indication

quantity value provided by a measuring instrument or a measuring system (JCGM 200:2012);

Project: ISO IEC Guide 99, C51

NOTE 1: An indication may be presented in visual or acoustic form or may be transferred to another device. An indication is often given by the position of a pointer on the display for analog outputs, a displayed or printed number for digital outputs, a code pattern for code outputs, or an assigned quantity value for material measures (JCGM 200:2012); NOTE 2: An indication and a corresponding value of the quantity being measured are not necessarily values of quantities of the same kind (JCGM 200:2012); NOTE 3: An indication is a signal or reading from a measuring system. An indication is often given by the position of a pointer on the display for analog outputs, a displayed or printed number for digital outputs, a code pattern for code outputs, or an assigned quantity value for material measures.


indication

(of a measuring instrument) value of a quantity provided by a measuring instrument (VIM93);

Project: ISO CD 18113-1, ISO CD 18113-2, ISO CD 18113-3

NOTE 1: The value read from the displaying device may be called the direct indication; it is multiplied by the instrument constant to give the indication; NOTE 2: The quantity may be the measurand, a measurement signal, or another quantity to be used in calculating the value of the measurand; NOTE 3: For a material measure, the indication is the value assigned to it.


indication interval

set of quantity values bounded by extreme possible indications (JCGM 200:2012);

Project: ISO IEC Guide 99

NOTE 1: An indication interval is usually stated in terms of its smallest and greatest quantity values, for example, "99 V to 201 V" (JCGM 200:2012); NOTE 2: In some fields, the term is "range of indications" (JCGM 200:2012).


indicator-labeled immunoassays

a group of immunoassays in which the antibodies are labeled with an indicator (commonly enzyme, fluorescent, chemiluminescent, radioisotope). The positive reaction between labeled antibodies and/or antigens is detected by a system that measures some property of the indicator molecule. These are mostly heterogeneous assays that require the separation of the bound from the free fractions;

Project: H59

NOTE: Examples include enzyme-linked immunosorbent assays, chemiluminescence immunoassays, fluorescence immunoassays, and radioimmunoassays.


indigenous

originating in a particular region or environment; occurring naturally in an area


indirect agglutination

the agglutination technique in which antigen first is coated artificially onto particulate surfaces, either by physical absorption, or chemical or immunochemical linkage. These antigen-laden particles can then be used to detect the presence of the corresponding specific agglutinins in test material. Agglutination results by cross-linking of the antigen-bearing particles onto an extensive antigen-antibody lattice, i.e., in detectable agglutination of the particles.

Project: Dl01


indirect analysis

systems that require dilution of the sample;

Project: C29

NOTE: These include some ion-selective, electrode-based systems, as well as flame emission photometry and atomic absorption.


indirect antiglobulin technique

an analytical method in which a particle (eg, erythrocyte or bacterium) is used to detect the presence of soluble incomplete antibodies by first causing it to react with test serum, with the subsequent addition of antiglobulin reagent resulting in complete agglutination (Cf. DI1).

Project: DL01


indirect antihuman globulin test

(IAT) a test in which AHG is used to detect antibody bound to red cell in vitro.

Project: ILA33


indirect contact transmission

the transfer of an infectious agent from one patient to another through a contaminated intermediate object or individual

Project: POCT04


indirect cost

a cost that cannot be identified directly with a particular activity, service, or product of the entity incurring the cost

Project: GP45

NOTE: Indirect costs are usually apportioned among an entity’s services in proportion to each service’s share of direct costs.


indirect cost

an expense (such as for administration, marketing, computing, maintenance, security, supervision) incurred in joint usage and therefore difficult to assign to or identify with a specific cost object or cost center and that is usually constant for a wide range of output; usually grouped with “fixed costs.”

Project: QMS20


indirect FTH measurement procedures

measurement procedures in which the FTH concentration is inferred from measurements of the total hormone concentration and the FTH fraction (e.g., by ED or SD) or a quantity reflecting the FTH fraction (e.g., fractional hormone uptake by a solid adsorbent such as solid phase antibody, ion-exchange resin, etc.).

Project: C45


indirect lighting

lighting by lamps that direct the light upward towards the ceiling


indirect susceptibility test

a procedure based on inoculation of drug-containing media using organisms grown in culture.

Project: M24


indistinguishable

in bacterial strain typing, the results for two isolates are described as “indistinguishable” when both isolates give the same results; by definition, such isolates represent the same strain within that typing system (MM11);

Project: MM11

NOTE 1: The term “identical” may be used for precise typing systems, such as nucleotide sequencing, but is not appropriate for analog systems, such as those based on restriction fragment length polymorphisms, which have inherent limits of resolution; NOTE 2: See also different, similar.


individualized quality control plan

a voluntary quality control option, effective in the United States as of January 1, 2016, that allows Clinical Laboratory Improvement Amendment–certified laboratories performing nonwaived testing to develop customized QC plans based on risk management for use in their health care settings.

Project: M52


inductance

a magnetic field produced by the presence of an electric current

Project: GP28


infection

the entry and multiplication of an infectious agent in the body of a person or animal with or without clinical symptoms;

Project: GP05

NOTE: Infection also means the entry of a toxin of an etiologic agent in the body of a person with or without clinical symptoms.


infectious agent

any microorganism that can invade body tissue and multiply, causing infection (Cf. POL1/2)

Project: POL1/2


infectious agent

a biological agent that can invade and multiply in body tissues, causing a condition that may be clinically unapparent or may result in the development of a disease.

Project: M29


infectious substance

a substance that contains a viable microorganism or its toxin, or a viral nucleic acid that is known, or is specified, to cause disease in animals or humans (Cf. H5)

Project: H05


infectious substance

a viable microorganism or its toxin that is associated with human disease, capable of producing infection with or without disease, and is listed in the National Institutes of Health (NIH) Guidelines for Research Involving Recombinant DNA Molecules, Appendix B, Classification of Human Etiologic Agents on the Basis of Hazard.

Project: GP05


infectious substance, Category A

infectious substance in a form that, when exposure to it occurs, is capable of causing permanent disability or life-threatening or fatal disease in an otherwise healthy human or animal;

Project: M29

NOTE: Infectious substances, Category A are assigned the following the United Nations (UN) numbers and proper shipping names: 1) UN 2814, Infectious Substance, affecting humans; or 2) UN 2900, Infectious Substance, affecting animals only.


infectious waste

includes wastes containing, or potentially containing, pathogens of sufficient virulence and quantity so that exposure to the waste by a susceptible host could result in the development by that host of a communicable disease;

Project: GP05

NOTE 1: Also included in infectious waste are regulated waste (as defined by OSHA under the blood-borne pathogen rules), and all but the “unused sharps” category of regulated medical waste (as defined by the 1988 Medical Waste Tracking Act, which has been adopted by some states); NOTE 2: This waste type is also referred to as “medical waste,” “biohazardous waste,” “red bag waste,” and “regulated medical waste.”


infectious waste

waste containing or assumed to contain pathogens of sufficient virulence and quantity, so that exposure (eg, inhalation or percutaneous injury) to the waste by a susceptible host could result in a communicable disease;

Project: M29, POCT10

NOTE 1: Also included in infectious waste are regulated waste (as defined by the Occupational Safety and Health Administration under the blood-borne pathogen rules), and all but the “unused sharps” category of regulated medical waste (as defined by the 1988 Medical Waste Tracking Act, which has been adopted by some states); NOTE 2: This waste type is also referred to as “medical waste,” “biohazardous waste,” “red bag waste,” and “regulated medical waste.”


influence quantity

quantity that, in a direct measurement, does not affect the quantity that is actually measured, but affects the relation between the indication and the measurement result (JCGM 200:2012);

Project: ISO IEC Guide 99

EXAMPLE 1: Frequency in the direct measurement with an ammeter of the constant amplitude of an alternating current (JCGM 200:2012); EXAMPLE 2: Amount-of-substance concentration of bilirubin in a direct measurement of haemoglobin amount-of-substance concentration in human blood plasma (JCGM 200:2012); EXAMPLE 3: Temperature of a micrometer used for measuring the length of a rod, but not the temperature of the rod itself, which can enter into the definition of the measurand (JCGM 200:2012); EXAMPLE 4: Background pressure in the ion source of a mass spectrometer during a measurement of amount-of-substance fraction (JCGM 200:2012); NOTE 1: An indirect measurement involves a combination of direct measurements, each of which may be affected by influence quantities (JCGM 200:2012); NOTE 2: In the GUM, the concept ‘influence quantity’ is defined as in the second edition of the VIM, covering not only the quantities affecting the measuring system, as in the definition above, but also those quantities that affect the quantities actually measured. Also, in the GUM, this concept is not restricted to direct measurements (JCGM 200:2012).


Information Access Service

(IAS) advertises capabilities of IrDA Devices;

Project: POCT01

NOTE: Also termed IrLMP-IAS.


information supplied by the manufacturer

all printed, written, graphic, or other information annexed to, or accompanying an in vitro diagnostic reagent (modified from ISO 19001)

Project: ISO 19001, M50


information supplied by the manufacturer

information related to identification, description, safety, and use of an in vitro diagnostic medical device; including, for example, labels, instructions for use, and promotional materials, but excluding shipping documents, safety data sheets, and catalogues (ISO TR 18112-1).

Project: ISO CD 18112-1, M50


information supplied by the manufacturer

(labeling) printed, written, graphic, or other information affixed to, or accompanying an in vitro diagnostic medical device, including instructions for use and labels on any of its packaging (modified from ISO 18113-1)

Project: ISO 15197


information supplied by the manufacturer

written, printed,  or graphic matter affixed to an IVD medical device or any of its containers or wrappers or provided for use with an IVD medical device, related to identification, technical description, and use of the IVD medical device, but excluding shipping documents (ISO 19001)

Project: ISO 19001


information supplied by the manufacturer

written, printed, or graphic matter affixed to an IVD medical device or any of its containers or wrappers or provided for use with an IVD medical device,
related to identification and use, and giving a technical description, of the IVD medical device, but excluding shipping documents (ISO 18113-1)

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3

NOTE 1: In IEC standards, documents provided with a medical device and containing important information for the responsible organization or operator, particularly regarding safety, are called “accompanying documents” (ISO 18113-1); NOTE 2: Catalogues and material safety data sheets are not considered labelling of IVD medical devices (ISO 18113-1); EXAMPLES: Labels, instructions for use (ISO 18113-1). 


information supplied by the manufacturer with the medical device

all written, printed, or graphic matter on a medical device or any of its containers or wrappers, or accompanying a medical device, relating to the identification, technical description, and use of the medical device, but excluding shipping documentation and promotional material (ISO 15198)

Project: ISO 15198, ISO CD 17593, ISO 15197, ISO/DIS 17593

NOTE: In some countries, information supplied by the manufacturer is called "labelling" (ISO 15198).


information technology support

customer support staff familiar with and responsible for the maintenance of computer hardware, operating system software, commercial off-the-shelf software components, and networking environment.

Project: AUTO11


informed consent

the process by which a person voluntarily confirms the willingness to participate in a particular medical procedure, after having been informed of all aspects of the procedure that are relevant to the decision to participate;

Project: MM19, MM20, POCT12, MM22

NOTE: Informed consent is documented by means of a written, signed, and dated informed consent form.


infrared

(IR) the physical layer typically used by infrared data association (IrDA) devices.

Project: POCT01


infrared

(IR) the transmission of data using light in the lower energy, longer wavelength range by infrared data association (IrDA) devices (CLSI document POCT02).

Project: POCT02


Infrared Data Association

(IrDA) an organization that creates and promotes interoperable, low-cost infrared data interconnection standards (www.irda.org);

Project: POCT01

NOTE: ‘IrDA’ also refers to the protocol stack authored by that group.


inhibition

components within the clinical specimen or exogenous substances introduced during specimen collection/processing that reduce amplification or detection.

Project: MM03, MM22


inhibition

reduction in amplification or detection of products causing false-positive or false-negative results in a test system due to components within a clinical specimen or exogenous substances introduced during specimen collection or processing

Project: M55


inhibitor

in biochemistry, any substance or agent that inhibits an enzymatic reaction, especially important for PCR-based clinical assays.

Project: MM13


in-house developed assay

See laboratory-developed assay.

Project: I/LA28


inner filter effect

an apparent decrease in emission quantum yield and/or distortion of bandshape as a result of reabsorption of emitted radiation, or absorption of incident radiation by a species other than the intended primary absorber (IUPAC Compendium of Chemical Technology, 2nd ed: 1997).

Project: I/LA24


inoculation

implanting microorganisms or other substances into a culture medium to allow them to grow (Cf. POL1/2)

Project: POL1/2


inoculum

number of microorganisms in a suspension, calculated with respect to the final volume (modified from ISO 20776-1)

Project: M52

NOTE 1: A suspension of microorganisms used to inoculate a microbial identification system or antimicrobial susceptibility testing system; NOTE 2: The inoculum is expressed as colony-forming units per milliliter (CFU/mL) (modified from ISO 20776-1).


inoculum

number of bacteria in a suspension, calculated with respect to the final volume (ISO 20776-1)

Project: ISO 20776-1

NOTE 1: The inoculum is expressed as colony-forming units per milliliter (CFU/mL) (ISO 20776-1); NOTE 2: A suspension of microorganisms used to inoculate a microbial identification system or antimicrobial susceptibility testing system. 


inoculum

a substance, or portion of a specimen, implanted in a culture medium (Cf. POL1/2)

Project: POL1/2


inoculum

microorganisms dispensed or mixed in a culture medium or microbial identification system prior to testing.

Project: M50


inoculum effect

change in MIC related to change in inoculum (ISO 20776-1)

Project: ISO 20776-1


input quantity

See input quantity in a measurement model.

Project: C51


input quantity in a measurement model

quantity that must be measured, or a quantity, the value of which can be otherwise obtained, in order to calculate a measured quantity value of a measurand (JCGM 200:2008);

Project: ISO IEC Guide 99, C51

EXAMPLE 1: When the length of a steel rod at a specified temperature is the measurand, the actual temperature, the length at that actual temperature, and the linear thermal expansion coefficient of the rod are input quantities in a measurement model (JCGM 200:2012); NOTE 1: An input quantity in a measurement model is often an output quantity of a measuring system (JCGM 200:2012); NOTE 2: Indications, corrections, and influence quantities can be input quantities in a measurement model (JCGM 200:2012); EXAMPLE 2: The temperature, cofactor concentrations, duration of incubation, and change in absorbance due to the change in product concentration can be input quantities in a measurement model for catalytic concentration of an enzyme in blood plasma (JCGM 200:2008 § 2.50).


input station

part of an automation line at which specimens are placed to begin transport on line


input variable

the given value that is used as a reference (independent variable) and against which the output variable is compared;

Project: EP06

NOTE: The input variable is represented by X with individual values of X noted by xi (i represents an individual observation); its value is plotted along the X-axis (abscissa).


input variable

the value {and/or random variable} that is used as a reference (independent variable) and against which the output variable (dependent) is compared;

Project: NRSCL08

NOTE: The input variable is represented by X; the subscript may be used to represent an individual observation and its values are plotted along the x-axis (abscissa). (Cf. EP6)


input variable

the value, usually represented by x, that is used as a reference (independent variable) and against which the output variable is compared.


in-range result

see expected range.

Project: NBS06


in-range result

screening result that is within the expected range of testing results established for a particular condition.


in-range result

screening result that is within the expected range of normal/negative testing results established for a particular condition

Project: NBS03


insertion

addition of one or more nucleotides into nucleic acid sequence (MM18).

Project: MM18


insertion

the addition of one or more nucleotide base pairs (bps) into a DNA sequence. Insertion mutations can occur in microsatellite regions due to the DNA polymerase slipping;

Project: MM19

NOTE: Insertions can be anywhere in size from one bp incorrectly inserted into a DNA sequence to a section of one chromosome inserted into another.


insertion/deletion

a variant characterized by an insertion, a deletion, or a combination of both a deletion and an insertion at the same site;

Project: MM09

NOTE 1: A sequence variant arising from both an insertion and a deletion; NOTE 2: Sometimes used in a general sense to describe the category of variants including both insertions and/or deletions.


inside liquid storage room

one-hour fire-rated room suitable for storage of flammable liquids located inside a building

Project: QMS04


installation qualification

confirmation that the facilities and supporting systems at a proposed installation site are adequate to support proper operation of an instrument or system.

Project: MM09


installation qualification

(IQ) confirmation that each component of the automated system has been installed according to the vendor’s specifications and that the functional tests have been performed and documented with expected results.

Project: ILA33


installation qualification

a set of formal checks and records that confirms the equipment or process and its components, including any integral hardware or software, were supplied as ordered and properly installed in the laboratory or other environment;

Project: QMS18

NOTE: Installation qualification can be performed by the manufacturer’s technical service engineer.


Institute of Electrical and Electronics Engineers

(IEEE) an international, ANSI-accredited standards development organization dedicated to the advancement of electrical and information technologies;

Project: POCT01

NOTE: Among its many roles, the IEEE sets standards for the electronics industry such as IEEE Standard 1073 for Medical Device Communications and IEEE Standard 802.3, which forms much of the lower-layers foundation for the Internet (www.ieee.org).


Institute of Electrical and Electronics Engineers

(IEEE) an international, ANSI-accredited standards development organization dedicated to the advancement of electrical and information technologies (CLSI document POCT02);

Project: POCT02

NOTE: Among its many roles, the IEEE sets standards for the electronics industry such as IEEE Standard 1073 for Medical Device Communications and IEEE Standard 802.3, which forms much of the foundation for the Internet (www.ieee.org) (CLSI document POCT02).


institutional review board

(IRB) in the United States, the standing committee in a medical school, hospital, or other health care facility that is charged with ensuring the safety and well-being of human subjects involved in research

Project: GP45

NOTE 1: The IRB is responsible for ethical review of research proposals; NOTE 2: Many synonyms are used in other countries (eg, Ethical Review Committee, Research Ethics Board); NOTE 3: All research, including epidemiological research, that involves human subjects must be approved by an institutional review board or equivalent body.


instructions for use

information supplied by the manufacturer with an in vitro diagnostic medical device concerning the safe and proper use of the reagent or the safe and correct operation, maintenance, and basic troubleshooting of the instrument (ISO 15198)

Project: ISO 15197, ISO 17593, ISO 15198, ILA33, QMS13, EP23

NOTE 1: Instructions for use for in vitro diagnostic reagents for self-testing are described in EN 376 and ISO/DIS 18113-4; NOTE 2: Instructions for use for in vitro diagnostic instruments for self-testing are described in EN 592 and ISO/DIS 18113-4; NOTE 3: Instructions for use may take the form of package insert sheets and/or user manuals.


instructions for use

information supplied by the manufacturer to enable the safe and proper use of an IVD medical device (ISO 18113-1)

Project: ISO 18113-1

NOTE: Includes the directions supplied by the manufacturer for the use, maintenance, troubleshooting and disposal of an IVD medical device, as well as warnings and precautions (ISO 18113-1).


instructions for use

information required by the user for the safe and effective use of a medical device;

Project: ISO CD 18112-1

NOTE: Instructions for use for in vitro diagnostic medical devices may take the form of package insert sheets, user manuals, and/or other media.


instructions for use

information supplied by the manufacturer to enable the safe and proper use of an IVD medical device (ISO 18113-1)

Project: M52

NOTE 1: Includes the directions supplied by the manufacturer for the use, maintenance, troubleshooting, and disposal of an in vitro diagnostic medical device, as well as warnings and precautions (ISO 18113-1); NOTE 2: Includes information concerning the safe and proper use of the reagent or the safe and correct operation, maintenance, quality control guidelines (streamlined and regular), and basic troubleshooting of the instrument; NOTE 3: Modification from these instructions constitutes a modified system or off-label usage.


instructions for use

information required by the user for the safe and proper use, maintenance, troubleshooting and disposal of an IVD medical device (EN 375);

NOTE: Instructions for use for in vitro diagnostic medical devices may take the form of insert leaflets, user manuals, and/or other media.


instructions for use

(product insert) information supplied by the manufacturer with an in vitro diagnostic medical device concerning the safe and proper use of the reagent or the safe and correct operation, maintenance, quality control guidelines (streamlined and regular), and basic troubleshooting of the instrument (modified from ISO 15198)

Project: M50

NOTE: Modification from these instructions constitutes a modified MIS.


instructions for use

information supplied by the manufacturer with a test system concerning the safe and proper use of the reagent or the safe and correct operation, maintenance, and basic troubleshooting of the test system (modified from ISO 15198)

Project: EP18


instrument

a device that will give analytical answers as a result of electrical or mechanical measurements on an element, compound, solution, etc.

Project: AUTO01, M29


instrument

an analytical unit that uses samples to perform chemical or physical assays (eg, chemistry analyzer, hematology analyzer)

Project: POCT04, AUTO01, AUTO02


instrument

an analytical unit that performs chemical or physical assays on samples (eg, chemistry analyzer, hematology analyzer).

Project: AUTO03


instrument constant

coefficient by which the direct indication of a measuring instrument must be multiplied to give the indicated value of the measurand or of a quantity to be used to calculate the value of the measurand (VIM93);

NOTE 1: Multirange measuring instruments with a single display have several instrument constants that correspond, for example, to different positions of a selector mechanism; NOTE 2: Where the instrument constant is the number one, it is generally not shown on the instrument.


instrument output

the result of a measurement by an instrument;

Project: EP06

NOTE: The instrument output need not be the final analytical result. (Cf. EP6)


instrument verification

a documented procedure for ensuring that point-of-care blood glucose meter instruments are performing according to the manufacturer's established criteria.

Project: POCT12


instrumental bias

average of replicate indications minus a reference quantity value (JCGM 200:2012).

Project: ISO IEC Guide 99


instrumental drift

continuous or incremental change over time in indication, due to changes in metrological properties of a measuring instrument (JCGM 200:2008);

Project: ISO IEC Guide 99

NOTE: Instrumental drift is related neither to a change in a quantity being measured nor to a change of any recognized influence quantity (JCGM 200:2012).


instrumental measurement uncertainty

component of measurement uncertainty arising from a measuring instrument or measuring system in use (JCGM 200:2012);

Project: ISO IEC Guide 99

NOTE 1: Instrumental measurement uncertainty is obtained through calibration of a measuring instrument or measuring system, except for a primary measurement standard for which other means are used (JCGM 200:2012); NOTE 2: Instrumental uncertainty is used in a Type B evaluation of measurement uncertainty (JCGM 200:2012); NOTE 3: Information relevant to instrumental measurement uncertainty may be given in the instrument specifications (JCGM 200:2012).


instrument-specific ISI

See thromboplastin-specific ISI.

Project: H54


integer mass

the mass expressed as a whole number (C50);

Project: C50

NOTE: In contrast, the exact mass value has a decimal component determined by the precision of the mass measurement (CLSI document C50).


integral

consisting of one piece, such as an integral baseboard with vinyl flooring, or an integral sink with countertop

Project: QMS04


integral biomarker

biomarker that is used for clinical decision making within clinical trials and is essential for the performance of the trial;

Project: MM23

NOTE: These biomarkers may include prognostic, predictive, pharmacogenomic, or occasionally pharmacodynamic markers and are used to determine patient eligibility for a trial, a patient’s assignment to therapy, dose selection, or patient stratification within a trial.


integrated biomarker

biomarker that is evaluated on all patients within a trial or in a statistically predefined subset, but is not used for medical decision making;

Project: MM23

NOTE: Integrated biomarkers are intended for clinical research or development of a marker and its corresponding assay for use in a subsequent trial.


integrated functional control

control material that is inherent in a reagent component of a measuring system, intended by the manufacturer to verify the performance of the measuring system (ISO 17593)

Project: ISO 17593

NOTE: The integrated functional control is run concurrently with a patient measurement, includes a reactive component, and provides a functional check of the procedure. The integrated control results must be within a predefined measurement interval for the measured value to be displayed (ISO 17593).


integrated test system

a lupus anticoagulant test system that simultaneously incorporates a screening, confirmatory, and mixing test (no step can be performed independently), eg, the hexagonal phase phospholipid neutralization test.

Project: H60


integrating measuring instrument

measuring instrument that determines the value of a measurand by integrating a quantity with respect to another quantity (VIM93) EXAMPLE electrical energy meter. (VIM93)


integrity

See data integrity, system integrity. (RFC 2828)

Project: AUTO09


integrity

(molecular, RNA) a measure of functionality, typically of an RNA molecule, by assessing intactness (full-length), 3´ poly(A) and 5´ cap structures, as well as purity.

Project: MM13


intended use

use for which a product, process, or service is intended according to the specifications, instructions, and information provided by the manufacturer (ISO 14971)

Project: EP19, POCT17, ISO 14971, EP18, QMS13, EP14

NOTE 1: The clinical use for which the measurement procedure was originally designed; NOTE 2: The concept includes definition of the measurand, the target condition, and the clinical use of the measurement procedure, which may include screening, diagnosis, prognosis, and/or monitoring of patients.


intended use

the clinical use for which the measurement procedure was originally designed;

NOTE: The concept includes definition of the measurand, the target condition, and the clinical use of the measurement procedure, which may include screening, diagnosis, prognosis, and/or monitoring of patients.


intended use

objective intent of an IVD manufacturer regarding the use of a product, process, or service as reflected in the specifications, instructions, and information supplied by the IVD manufacturer (ISO 18113-1)

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3, POCT09

NOTE 1: Intended use statements for IVD labelling can include two components: a description of the functionality of the IVD medical device (eg, an immunochemical measurement procedure for the detection of analyte “x” in serum or plasma), and a statement of the intended medical use of the examination results (ISO 18113-1); NOTE 2: This is the definition adopted by the GHTF in Global Harmonization Task Force (GHTF), Labelling for Medical Devices, Final DocumentGHTF/SG1/N43:2005, 3 June 2005 (ISO 18113-1).


intended use

objective intent of the manufacturer or other legal entity, or person, under whose name a device is placed on the market, in respect of the application and performance of the device, as indicated in the information supplied by the manufacturer

Project: ISO/CD 18112-1


intended use population

specific populations for which measurement procedures are designed to be used;

Project: EP19

NOTE 1: The intended use and validation criteria are determined by the intended use population, which may be defined in terms of age, sex, existence of comorbidities, and other issues; NOTE 2: Some measurement procedures are designed for very specific populations, eg, newborn screening or prediction of risk of inheritance of an inborn metabolic disease.


intention tremor

a dyskinetic disorder consisting of wide tremor during voluntary movements. The tremor worsens when a person is moving. It is the result of dysfunction of the cerebellum and is therefore part of the characteristic symptoms of cerebellar ataxia.

Project: MM19


intention-to-treat analysis

a strategy for analyzing data in which all participants are included in the group to which they were assigned, whether or not they completed the intervention given to the group

Project: GP45

NOTE: Intention-to-treat analysis prevents bias caused by the loss of participants, which may disrupt the baseline equivalence established by random assignment and which may reflect nonadherence to the protocol.


intercept

the point where a function intersects an axis;

Project: NRSCL08, EP06

NOTE: The y-intercept is the value of the y-variable when the x-variable has a value of zero.


intercept

the value of a variable, when the value for the other variables is zero;

Project: NRSCL08

NOTE 1: The y-intercept is the value of the y-variable when the x-variable has a value of zero; NOTE 2: The x-intercept is the value of the x-variable when the y-variable has a value of zero; NOTE 3: For example, a line y = mx + b has two intercepts: at the y-axis, the y-intercept is the point (0,b) and at the x-axis, the x-intercept is the point (- b/m, 0). Often the intercept is referred to as the value of the variable whose axis is intercepted, e.g., b for the y-intercept; NOTE 4: There are as many potential intercepts as the function has variables; NOTE 5: Often the term "intercept" is used to mean "y-intercept." To avoid ambiguity, refer to the variable for which a value is sought when all other variables are set to zero.


intercept

1) the point where a function intersects an axis; 2) the value of a variable, when the value for the other variables is zero;

Project: EP06

NOTE: The y-intercept is the value of the y-variable when the x-variable has a value of zero.


interface

a connection between computer systems or devices to allow communication and exchange of data (POCT02).

Project: POCT02


interface

1) a shared boundary between two functional units, defined by functional characteristics, common physical interconnection characteristics, signal characteristics, and other characteristics, as appropriate; the concept involves the specification of the connection of two devices having different functions; 2) a point of communication between two or more processes, persons, or other physical entities; 3) a peripheral device that permits two or more devices to communicate (ISO/IEC International Standard 812).

Project: AUTO08, ILA33


interference

in clinical chemistry, a cause of clinically significant bias in the measured analyte concentration due to the effect of another component or property of the sample;

Project: EP07, C53

NOTE: The effect may result from nonspecificity of the detection system, suppression of an indicator reaction, inhibition of the analyte (enzymes), or any other cause of specimen-dependent bias.


interference

artifactual increase or decrease in apparent concentration or intensity of an analyte due to the presence of a substance that reacts nonspecifically with the measurement system.

Project: C53


interference

artifactual increase or decrease in apparent concentration or intensity of an analyte (measurand) due to the presence of a substance that reacts nonspecifically with either the detecting reagent or the signal itself.

Project: EP11, ILA18, MM10, LA01, H20, H26


interference

in laboratory medicine and clinical chemistry, a cause of clinically significant bias in the measured analyte concentration due to the effect of another component or property of the sample.

Project: C56


interference

(analytical) the effect of substances in the sample that make the test give wrong results;

Project: POCT08

NOTE: Interferences can make a test turn positive when the material to be measured (the “target”) is present, keep it from turning positive even though target is present, or make the measured amount of target significantly different from the real value. Interferences may be identified or unidentified substances; some are well known, such as soap added to urine for drug of abuse testing to keep it from turning positive or ethylenediaminetetraacetic acid (EDTA) anticoagulant from a blood collection tube causing extremely low calcium values; others are sporadic and difficult to characterize.


interference claim

statement describing the effect that a substance may have on the results of a measurement procedure;

Project: EP07, C56

NOTE: It is typically included in the product labeling under "Limitations of the Method."


interference criteria

maximum allowable effect due to an interfering substance, normally based on the bias from the true value that has the potential to alter a physician's diagnosis, treatment, or management of a patient.

Project: EP07, C56


interference criteria

maximum allowable interference resulting in the bias of measured analyte concentration from the true value that has the potential to alter a physician's diagnosis, treatment, or management of a patient.

Project: EP07


interference screen

in the evaluation of an analytical system, a series of tests performed with high concentrations of commonly occurring substances to identify those that are likely to cause interference.

Project: EP07


interference sensitivity

susceptibility of a measurement procedure to error caused by interference from other components or properties of the sample.

Project: EP07, C56


interferent

substance or matrix that alters the expected result of a measurement procedure by cross-reactivity or other means

Project: C52


interferent

substance or matrix that alters the expected result of an assay by cross-reactivity or other means.

Project: I/LA28, C56


interfering substance

a component of the sample, other than the analyte, that causes a bias in the measured analyte concentration.

Project: EP07, C56


interfering substance

this term is defined the way JCGM 200:2012 defines "influence quantity" (quantity that, in a direct measurement, does not affect the quantity that is actually measured, but affects the relation between the indication and the measurement result).

Project: EP07


interfering substances

endogenous (eg, blood components, acidic polysaccharides) or exogenous (eg, talc, anticoagulant) substances in clinical specimens that can cause incorrect (false-positive or false-negative) results in a test system

Project: ILA33, M55, MM22


interfering substances

endogenous (eg, blood components, acidic polysaccharides) or exogenous (eg, talc, anticoagulant) substances in clinical specimens that can cause false-positive or false-negative results in a test system. It can also be used to refer to nontarget organisms or sequences that may result in false-positive results.

Project: MM03


interim analysis

any data analysis that is performed during the clinical evaluation and before the evaluation is completed;

Project: I/LA21

NOTE 1: Analyses performed at intervals throughout the evaluation provide the sponsor with estimates of the new assay’s performance; NOTE 2: These estimates are of limited validity due to insufficient sample size.


interinstrument bias

the difference observed by comparing two specified instruments’ or laboratories’ methods under specified conditions of analysis, concentration range, method, etc.

Project: NRSCL08


interlaboratory comparisons

organization, performance, and evaluation of measurements or tests on the same or similar items by two or more laboratories in accordance with predetermined conditions (ISO Guide 43-1).

Project: GP35


intermediate

(I) for breakpoints, bacterial strain inhibited in vitro by a concentration of an antimicrobial agent that is associated with uncertain therapeutic effect (ISO 20776-1)

Project: ISO 20776-1, ISO 20776-2

NOTE 1: Bacterial strains are categorized as intermediate by applying the appropriate breakpoints in a defined phenotypic test system (ISO 20776-1); NOTE 2: This class of susceptibility implies that an infection due to the isolate can be appropriately treated in body sites where the drugs are physiologically concentrated or when a high dosage of drug can be used (ISO 20776-1); NOTE 3: This class also indicates a "buffer zone," to prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations (ISO 20776-1); NOTE 4: These breakpoints can be altered due to changes in circumstances (e.g., changes in commonly used drug dosages, emergence of new resistance mechanisms) (ISO 20776-1).


intermediate antimicrobial susceptibility test interpretive category

the “intermediate” category includes isolates with antimicrobial agent MICs that approach usually attainable blood and tissue levels and for which response rates may be lower than for susceptible isolates and/or available data do not permit them to be clearly categorized as either “susceptible” or “resistant.” This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations.

Project: M27


intermediate antimicrobial susceptibility test interpretive category

a category that includes isolates with antimicrobial agent MICs that approach usually attainable blood and tissue levels and for which response rates may be lower than for susceptible isolates. The intermediate category implies clinical efficacy in body sites where the drugs are physiologically concentrated (eg, quinolones and β-lactams in urine) or when a higher than normal dosage of a drug can be used (eg, β-lactams). This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations, especially for drugs with narrow pharmacotoxicity margins.


intermediate antimicrobial susceptibility test interpretive category

for minimal inhibitory concentration, an interpretive category that implies that an infection due to the isolate may be appropriately treated in body sites where the drugs are physiologically concentrated or when a high dosage of drug can be used; also indicates a "buffer zone" that should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations.

Project: M24


intermediate antimicrobial susceptibility test interpretive category

a category that implies that an infection due to the isolate may be successfully treated in body sites where the drugs are physiologically concentrated or when a higher approved dosage of drug can be used; also indicates a “buffer zone” that should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations


intermediate antimicrobial susceptibility test interpretive category

a category that implies that an infection due to the isolate may be successfully treated in body sites where the drugs are physiologically concentrated or when a higher approved dosage of drug can be used; also indicates a “buffer zone” that should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations.

Project: VET05


intermediate antimicrobial susceptibility test interpretive category

a category that implies that an infection due to the isolate may be appropriately treated in body sites where the drugs are physiologically concentrated; also indicates a ¨buffer zone¨ that should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations.

Project: VET04


intermediate antimicrobial susceptibility test interpretive category

a category that includes isolates with antimicrobial agent MICs that approach usually attainable blood and tissue levels and for which response rates may be lower than for susceptible isolates and/or available data do not permit them to be clearly categorized as either “susceptible” or “resistant” (M44);

Project: M44

NOTE: This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations (M44).


intermediate measures of precision

precision under conditions where test results are obtained within the same facility but under changed conditions of operator, equipment, or time (modified from ISO 3534-1);

Project: ISO 3534-1

NOTE 1: The changed conditions must be indicated; NOTE 2: Repeatability is considered the smallest measure of precision, due to no changes in conditions (such as within-run precision), and reproducibility is considered to be the largest measure, with all test conditions changed (such as interlaboratory precision). Intermediate measures (such as between run precision, between day precision, within laboratory precision, etc.) should lie between the extremes.


intermediate precision

(measurement) measurement precision under a set of intermediate precision conditions of measurement (modified from JCGM 200:2012)

Project: ISO IEC Guide 99, C53, EP05

NOTE: Relevant statistical terms are given in ISO 5725-3:1994 (JCGM 200:2012).


intermediate precision

precision under conditions intermediate between reproducibility conditions and repeatability conditions (ISO 15198)

Project: ISO 15198, ISO CD 17593, ISO 15197, ISO DIS 17593

NOTE 1: The concept of intermediate levels of precision is described in ISO 5725-3 (ISO 15198); NOTE 2: Quantitative measures of intermediate precision depend on the stipulated conditions; NOTE 3: Intermediate precision provides an indication of the variability that will be experienced by a user in typical use.


intermediate precision

(measure) precision under intermediate precision conditions.

Project: I/LA28


intermediate precision condition of measurement

condition of measurement, out of a set of conditions that includes the same measurement procedure, same location, and replicate measurements on the same or similar objects over an extended period of time, but may include other conditions involving changes (JCGM 200:2012)

Project: QMS24, ISO IEC Guide 99

NOTE 1: The changes can include new calibrations, calibrators, operators, and measuring systems (JCGM 200:2012); NOTE 2: A specification for the conditions should contain the conditions changed and unchanged, to the extent practical (JCGM 200:2012); NOTE 3: In chemistry, the term "inter-serial precision condition of measurement" is sometimes used to designate this concept (JCGM 200:2012).


intermediate precision conditions

conditions where test results or measurement results are obtained with the same method, on identical test/measurement items in the same test or measurement facility, under some different operating conditions (ISO 3534-2)

Project: ISO 3434-2, EP05, EP15

NOTE 1: There are four elements to the operating conditions: time, calibration, operator, and equipment [ISO 3534-2]; NOTE 2: A test house is an example of a test facility. A metrology laboratory is an example of a measurement facility. [ISO 3534-2]; NOTE3:: The changed elements in operating conditions must be noted; this could include precision estimates commonly called, for example "between-run," "within-day," between-day," "within-device," and "within-laboratory."


intermediate precision conditions

where test results or measurement results are obtained with the same method, on identical test/measurement items in the same test facility, under some different operating condition;

Project: I/LA28

NOTE 1: There are four elements to the operating conditions: time, calibration, operator, and equipment; NOTE 2: The changed elements in operating conditions must be noted; this could include precision estimates commonly called, for example, "between-run," "within-day," "between-day," "within-device," and "within-laboratory"; NOTE 3: The changed elements in operating conditions must be noted; this could include precision estimates commonly called, for example “between-run,” “within-day,” “between-day,” “within device,” and “within-laboratory.”


intermediate precision conditions

conditions where independent test results are obtained with the same method on identical test items in the same laboratory or location, but where other variables such as operators, equipment, calibration, environmental conditions, and/or time intervals differ (ISO 15198)

Project: ISO 17593, ISO 15197, ISO 15198

NOTE 1: Intended to measure precision in conditions leading to variability representative of actual use. Quantitative measures of intermediate precision depend on the stipulated conditions; NOTE 2: conditions where independent measurement results are obtained with the same measurement method on identical samples in the same location, but where other variables such as operators, equipment, calibration, environmental conditions, and/or time intervals differ (ISO 17593).


intermediate precision of measurement

measurement precision under conditions intermediate between reproducibility conditions and repeatability conditions (ISO 17593)

Project: ISO 17593

NOTE 1: The concept of intermediate levels of precision is described in ISO 5725-3:1994; NOTE 2: Quantitative measures of intermediate precision depend on the stipulated conditions (ISO 17593); NOTE 3: Intermediate precision provides an indication of the variability that will be experienced by a user during typical use (ISO 17593).


internal control

a control that is placed in the same reaction tube as the specimen being analyzed;

Project: MM10

NOTE: An internal control will be subjected to exactly the same internal conditions and external parameters as any analyte present in the tube.


internal control

a nontarget sequence present in the same sample tube, which is coamplified to identify inhibition due to thermal cycler malfunction, suboptimal reagents or polymerase activity, or presence of inhibitory substances in the sample matrix; a defined amount of internal control can be used to quantify the target;

Project: MM17, MM06, MM19, MM20

NOTE: An internal control is placed in the same reaction tube as the specimen being analyzed. Thus, an internal control will be subjected to exactly the same internal conditions and external parameters as any analyte (measurand) present in the tube.


internal control

a nontarget sequence present in the same sample tube, which is coamplified to identify inhibition due to thermal cycler malfunction, suboptimal reagents or polymerase activity, or presence of inhibitory substances in the sample matrix; a defined amount of internal control can be used to quantify the target;

Project: MM22

NOTE: An internal control is placed in the same reaction tube as the specimen being analyzed. Thus, an internal control will be subjected to exactly the same internal conditions and external parameters as any measurand present in the tube.


internal control

cells of known phenotypic expression present in the sample analyzed (H42, H43);

Project: H42, H43

NOTE: Positive and/or negative expression and fluorescent intensity of such cells serve as process controls (H42, H43).


internal control

cells of known phenotypic expression present in the sample analyzed that serve to define levels of antigenic expression and serve as an indicator of assay specifications being fulfilled;

Project: H52

NOTE: Positive and/or negative expression and fluorescent intensity of such cells serve as process controls.


internal control

a nontarget sequence present in the same sample tube, which is coamplified in order to identify inhibition due to thermal cycler malfunction, suboptimal reagents or polymerase activity, or presence of inhibitory substances in the sample matrix;

Project: MM03

NOTE: An internal control is placed in the same reaction tube as the specimen being analyzed. Thus, an internal control will be subjected to exactly the same internal conditions and external parameters as any analyte present in the tube. Endogenous sample controls such as human gene targets can be used to assess that the specimen contains an adequate number of human cells.


internal failure cost

cost occurring before delivery or shipment of the product or furnishing of a service to the customer.

Project: QMS20


internal quality control

operational techniques and activities at the point of use that are used to fulfill requirements for quality of services;

Project: EN 375:1999

NOTE: Internal quality control comprises all steps of activity for production of results from collection of sample and measurement of a measurable quantity to reporting of result of measurement.


internal quality control

for the purposes of CLSI document C50, internal quality control (QC) is the evaluation of analytical performance that includes QC samples for which the analyst knows the expected measurement result;

Project: C50

NOTE 1: Internal QC materials can be made by weighing or spiking a known amount of analyte into the matrix that will be used for the clinical analysis (CLSI document C50); NOTE 2: Internal QC materials may also evaluate particular aspects of method performance, such as an analytical blank (CLSI document C50).


internal quality control

(IQC) set of procedures undertaken by laboratory staff for the continuous monitoring of operation and the results of measurements in order to decide whether results are reliable enough to be released.

Project: C51


internal quality control

procedures run in association with the measurement of patients' specimens to evaluate whether the analytical system is operating within predefined tolerance limits (Cf. H26)

Project: H26


internal standard

a chemical substance that is added in a constant amount to calibration standards and unknown samples to correct for loss of analyte during preexamination preparation (eg, solid phase extraction) or for matrix effects during analysis.

Project: C62


internal standard

in mass spectrometry, a stable isotope-labeled version of the chemical analyte that is added to a sample at a known concentration during processing to allow for quantitation of the analyte

Project: NBS04


international calibrator

calibrator whose value of a quantity is not traceable to the International System of Units (SI) but is assigned by international agreement.

Project: MM06


international conventional calibration material

See international conventional calibrator.


international conventional calibrator

calibrator whose value of a quantity is not metrologically traceable to the SI but is assigned by international agreement (ISO 17511)

Project: ISO 17511, X05

NOTE: The quantity is defined with respect to the intended clinical application (ISO 17511).


international conventional calibrator

calibrator whose quantity value is not metrologically traceable to the SI but is assigned by international agreement (ISO 15194)

Project: ISO 15194

NOTE: The quantity is defined with respect to the intended application (ISO 15194).


international conventional reference measurement procedure

measurement procedure yielding values that are not metrologically traceable to the SI but which by international agreement are used as reference values for a defined quantity (ISO 17511)

Project: ISO 17511, C45

NOTE: The quantity is defined with respect to the intended clinical application (ISO 17511).


international measurement standard

measurement standard recognized by signatories to an international agreement and intended to serve worldwide (JCGM 200:2012)

Project: ISO IEC Guide 99

EXAMPLE 1: The international prototype of the kilogram (JCGM 200:2012); EXAMPLE 2: Chorionic gonadotrophin, World Health Organization (WHO) 4th international standard 1999, 75/589, 650 International Units per ampoule (JCGM 200:2012); EXAMPLE 3: VSMOW2 (Vienna Standard Mean Ocean Water) distributed by the International Atomic Energy Agency (IAEA) for differential stable isotope amount-of-substance ratio measurements (JCGM 200:2012).


international measurement standard

standard recognized by an international agreement to serve internationally as the basis for assigning values to other standards of the quantity concerned (ISO 17511)

Project: X05, ISO 17511


international normalized ratio

(INR) patient’s prothrombin time measurement result, which has been standardized for the potency of the thromboplastin used in the measurement procedure and expressed relative to a normal population average (ISO 17593)

Project: ISO 17593, H54

NOTE 1: For a discussion of the use of INR, see Poller et al. (ISO 17593); NOTE 2: It is standardized using a World Health Organization (WHO) international reference thromboplastin preparation, and determined using the equation: INR = RISI, where R is the PT ratio obtained with the working thromboplastin; NOTE 3: Patient’s prothrombin time (PT) test result expressed as a ratio to a normal population (MNPT) which has been standardized (or normalized) for the potency of the thromboplastin used in the assay (modified from ISO 17593); NOTE 4: INR = (Plasma PT÷MNPT)ISI.


international normalized ratio

(INR) expression of the patient’s prothrombin time test result expressed as a ratio to a normal population control, which has been standardized (or normalized) for the potency to the thromboplastin used in the assay

Project: POCT14

NOTE 1: The INR is determined by using the equation: INR = RISI, where R is the PT ratio obtained with the working thromboplastin; NOTE 2: The ISI should be determined by standard protocols according to WHO guidelines and provided by the manufacturer to the user for a particular reagent/instrument combination or POC-CT system.


international normalized ratio

(INR) patient’s prothrombin time (PT) test result expressed as a ratio to the mean normal prothrombin time (MNPT) standardized (or normalized) for the potency of the thromboplastin used in the assay (modified from ISO 17593)

Project: H21

NOTE: INR = (Plasma PT ÷ MNPT)ISI.


international normalized ratio

(INR) the patient’s PT test result expressed as a ratio to a mean normal prothrombin time (MNPT), which has been standardized (or normalized) for the potency of the thromboplastin used in the assay (modified from ISO 17593)

Project: H47, H57

NOTE: INR = (Plasma PT÷MNPT)ISI.


international reference preparation

(IRP) reference calibrator maintained by the World Health Organization (ISO 17593)

Project: ISO 17593

NOTE: The IRP for thromboplastin is directly calibrated for potency against the original British comparative thromboplastin preparations used in the establishment of the INR system (ISO 17593).


international reference preparation

(IRP) a thromboplastin with defined biological activity used to calibrate other reference preparations and secondary or manufacturer’s standards

Project: H54, H47

NOTE 1: There are three species of IRP: bovine, rabbit, and human, which can be produced from original biological sources or other recombinant sources; NOTE 2: IRPs can only be used in combination with the manual technique (tilt-tube method, or other methods that have been validated); NOTE 3: WHO and European Union CRM standards are examples of IRPs ; NOTE 4: IRPs are also sometimes referred to as primary standards.


international reference preparation

a substance that has been characterized by chemical or physical means and that provides a measure against which national reference preparations and calibrators can be controlled

Project: H15

NOTE: International reference materials are not intended to be used in laboratory working procedures but serve as materials against which commercial products can be verified and evaluated.


International Sensitivity Index

(ISI) a quantitative measure, in terms of the first International Reference Preparation of thromboplastin, human, combined, coded 67/40, of the responsiveness of a prothrombin-time system to the defect induced by oral anticoagulants (WHO 880).

Project: H21, H54, H47


International Sensitivity Index

(ISI) a mathematical indicator of the responsiveness of a PT testing system to deficiencies of the vitamin K coagulation factors

Project: POCT14

NOTE 1: It is the comparative slope used to calculate the INR; NOTE 2: A low ISI indicates a highly responsive PT system and a high ISI indicates a poorly responsive system; NOTE 3: It is determined by standard protocols according to WHO guidelines and provided by the manufacturer to the user for a particular reagent/instrument combination.


international sensitivity index

(ISI) factor that allows the conversion of a patient's prothrombin time measurement result to international normalized ratio values (ISO 17593)

Project: ISO 17593

NOTE: For a discussion of the use of ISI and INR, see Poller et al (ISO 17593).


international standard

See international measurement standard.


International System of Quantities

system of quantities based on the seven base quantities: length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity (JCGM 200:2008);

Project: ISO IEC Guide 99

NOTE 1: This system of quantities is published in the ISO 80000 and IEC 80000 series Quantities and units (JCGM 200:2012); NOTE 2: The International System of Units (SI) (see 1.16) is based on the ISQ (JCGM 200:2012).


International System of Units

system of units, based on the International System of Quantities, their names and symbols, including a series of prefixes and their names and symbols, together with rules for their use, adopted by the General Conference on Weights and Measures (CGPM) (JCGM 200:2012);

Project: ISO IEC Guide 99

NOTE 1: The SI is founded on the seven base quantities of the ISQ and the names and symbols of the corresponding base units that are contained in the following table (JCGM 200:2012):

 

Base quantity

Base unit

Name

Symbol

length

mass

time

electric current

thermodynamic temperature

amount of substance

luminous intensity

metre

kilogram

second

ampere

kelvin

mole

candela

m

kg

s

A

K

mol

cd

 

NOTE 2: The base units and the coherent derived units of the SI form a coherent set, designated the "set of coherent SI units" (JCGM 200:2012); NOTE 3: For a full description and explanation of the International System of Units, see the current edition of the SI brochure published by the Bureau International des Poids et Mesures (BIPM) and available on the BIPM website (JCGM 200:2012); NOTE 4: In quantity calculus, the quantity ‘number of entities’ is often considered to be a base quantity, with the base unit one, symbol 1 (JCGM 200:2012); NOTE 5: The SI prefixes for multiples of units and submultiples of units are (JCGM 200:2012):

 

Factor

Prefix

Name

Symbol

1024

1021

1018

1015

1012

109

106

103

102

101

10-1

10-2

10-3

10-6

10-9

10-12

10-15

10-18

10-21

10-24

yotta

zetta

exa

peta

tera

giga

mega

kilo

hecto

deca

deci

centi

milli

micro

nano

pico

femto

atto

zepto

yocto

Y

Z

E

P

T

G

M

k

h

da

d

c

m

μ

n

p

f

a

z

y

 



international system of units

(SI) the coherent system of units adopted and recommended by the General Conference on Weights and Measures (CGPM) (VIM93).

Project: VIM93

 

NOTE: The SI is based at present on the following seven base units:

 

Quantity

SI base unit

Name

Symbol

length

mass

time

electric current

thermodynamic temperature

amount of substance

luminous intensity

metre

kilogram

second

ampere

kelvin

mole

candela

m

kg

s

A

K

mol

cd

 


international unit

an arbitrary unit assigned to a certified reference material by an international organization that is generally accepted as competent;

Project: Dl01

NOTE 1: Any recognized international organization can define an international unit; NOTE 2: An international unit of enzyme activity (U) is the amount of enzyme that will generate one molecule of product per minute under standard conditions; NOTE 3: The WHO-approved abbreviation for the international unit assigned to WHO International Biological Standards and WHO International Biological Reference Preparations under the control of the WHO expert Committee on Biological Standardization, is “IU,” rather then the SI recommendation “international unit” (Cf. DI1).


Internet Engineering Task Force

(IETF) large, open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet;

Project: AUTO09

NOTE: It is open to any interested individual.


Internet Protocol

(IP) an Internet Standard protocol (version 4 and version 6) that moves datagrams (discrete sets of bits) from one computer to another across an internetwork but does not provide reliable delivery, flow control, sequencing, or other end-to-end services that TCP provides. (See: IP address.) (RFC 2828)

Project: AUTO09


Internet Protocol security

(IPsec) 1) the name of the IETF working group that is specifying a security architecture and protocols to provide security services for Internet Protocol traffic; 2) a collective name for that architecture and set of protocols. (Implementation of IPsec protocols is optional for IP version 4, but mandatory for IP version 6.) (RFC 2828)

Project: AUTO09


interoperability

the ability of two or more systems or components to exchange information and to use the information that has been exchanged.

Project: AUTO08


interpolate

to insert, estimate, or find an intermediate term (in a sequence);

Project: H54

NOTE 1: (H54) INRs above 4.5 would be extrapolated, while those between 1 and 4.5 would be interpolated.


interpolation

the process of determining the value of a function or quantity between two or more points at which it has prescribed values, such as between calibrator values.

Project: NRSCL08


interpretive category

category derived from microbiological characteristics, pharmacokinetic/pharmacodynamic parameters, and clinical outcome data, when available

NOTE 1: Minimal inhibitory concentration (MIC) or zone diameter values generated by a susceptibility test can be interpreted based upon established breakpoints; NOTE 2: See breakpoint. 

           EXAMPLE:



Interpretive Category

Breakpoints*

MIC (µg/mL)

Zone Diameter (mm)

Susceptible

£ 4

³ 20

Susceptible-dose dependent

8–16

15–19

Intermediate

8–16

15–19

Resistant

³ 32

£ 14

Nonsusceptible

> 4

< 20

                  *Formerly “interpretive criteria.”



 

MIC or zone diameter value breakpoints or interpretive categories are established per CLSI document M23 for categories of susceptible, intermediate, and resistant (and susceptible-dose dependent and nonsusceptible, when appropriate).

Susceptible (S) – a category defined by a breakpoint that implies that isolates with an MIC at or below or zone diameters at or above the susceptible breakpoint are inhibited by the usually achievable concentrations of antimicrobial agent when the dosage recommended to treat the site of infection is used, resulting in likely clinical efficacy.

Susceptible-dose dependent (SDD) – a category defined by a breakpoint that implies that susceptibility of an isolate is dependent on the dosing regimen that is used in the patient. In order to achieve levels that are likely to be clinically effective against isolates for which the susceptibility testing results (either MICs or zone diameters) are in the SDD category, it is necessary to use a dosing regimen (ie, higher doses, more frequent doses, or both) that results in higher drug exposure than the dose that was used to establish the susceptible breakpoint. Consideration should be given to the maximum approved dosage regimen, because higher exposure gives the highest probability of adequate coverage of an SDD isolate. The drug label should be consulted for recommended doses and adjustment for organ function; NOTE: The concept of SDD has been included within the intermediate category definition for antimicrobial agents. However, this is often overlooked or not understood by clinicians and microbiologists when an intermediate result is reported. The SDD category may be assigned when doses well above those used to calculate the susceptible breakpoint are approved and used clinically, and where sufficient data to justify the designation exist and have been reviewed. When the intermediate category is used, its definition remains unchanged.

Intermediate (I) – a category defined by a breakpoint that includes isolates with MICs or zone diameters within the intermediate range, that approach usually attainable blood and tissue levels and for which response rates may be lower than for susceptible isolates; NOTE: The intermediate category implies clinical efficacy in body sites where the drugs are physiologically concentrated or when a higher than normal dosage of a drug can be used. This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations, especially for drugs with narrow pharmacotoxicity margins.

Resistant (R) – a category defined by a breakpoint that implies that isolates with an MIC at or above or zone diameters at or below the resistant breakpoint are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules and/or that demonstrate MICs that fall in the range in which specific microbial resistance mechanisms are likely, and clinical efficacy of the agent against the isolate has not been reliably shown in treatment studies.

Nonsuceptible (NS) – a category used for isolates for which only a susceptible breakpoint is designated because of the absence or rare occurrence of resistant strains. Isolates for which the antimicrobial agent MICs are above or zone diameters below the value indicated for the susceptible breakpoint should be reported as nonsusceptible; NOTE 1: An isolate that is interpreted as nonsusceptible does not necessarily mean that the isolate has a resistance mechanism. It is possible that isolates with MICs above the susceptible breakpoint that lack resistance mechanisms may be encountered within the wild-type distribution subsequent to the time the susceptible-only breakpoint was set; NOTE 2: The term “nonsusceptible” should not be used when describing an organism/drug category with SDD or intermediate and resistant interpretive categories. Isolates that are in the categories of “intermediate” or “resistant” could be called “not susceptible” rather than “nonsusceptible.”


interpretive category

category derived from microbiological characteristics, pharmacokinetic/pharmacodynamic parameters, and clinical outcome data, when available

Project: VET06

NOTE 1: Minimal inhibitory concentration (MIC) or zone diameter values generated by a susceptibility test can be interpreted based upon established breakpoints; NOTE 2: See breakpoint.           

           EXAMPLE:

Interpretive Category

Breakpoints*

MIC (µg/mL)

Zone Diameter (mm)

Susceptible

£ 4

³ 20

Intermediate

8–16

15–19

Resistant

³ 32

£ 14

Nonsusceptible

> 4

< 20

*Formerly “interpretive criteria.”


MIC or zone diameter value breakpoints or interpretive categories are established per CLSI document VET02 for categories of susceptible, intermediate, and resistant (and nonsusceptible, when appropriate).

Susceptible (S) – a category defined by a breakpoint that implies that isolates with an MIC at or below or zone diameters at or above the susceptible breakpoint are inhibited by the usually achievable concentrations of antimicrobial agent when the dosage recommended to treat the site of infection is used, resulting in likely clinical efficacy.

Intermediate (I) – a category defined by a breakpoint that includes isolates with MICs or zone diameters within the intermediate range, that approach usually attainable blood and tissue levels and for which response rates may be lower than for susceptible isolates; NOTE: The intermediate category implies clinical efficacy in body sites where the drugs are physiologically concentrated or when a higher than normal dosage of a drug can be used. This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations, especially for drugs with narrow pharmacotoxicity margins.

Resistant (R) – a category defined by a breakpoint that implies that isolates with an MIC at or above or zone diameters at or below the resistant breakpoint are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules and/or that demonstrate MICs that fall in the range in which specific microbial resistance mechanisms are likely, and clinical efficacy of the agent against the isolate has not been reliably shown in treatment studies.

Nonsuceptible (NS) – a category used for isolates for which only a susceptible breakpoint is designated because of the absence or rare occurrence of resistant strains. Isolates for which the antimicrobial agent MICs are above or zone diameters below the value indicated for the susceptible breakpoint should be reported as nonsusceptible; NOTE 1: An isolate that is interpreted as nonsusceptible does not necessarily mean that the isolate has a resistance mechanism. It is possible that isolates with MICs above the susceptible breakpoint that lack resistance mechanisms may be encountered within the wild-type distribution subsequent to the time the susceptible-only breakpoint was set; NOTE 2: The term “nonsusceptible” should not be used when describing an organism/drug category with intermediate and resistant interpretive categories. Isolates that are in the categories of “intermediate” or “resistant” could be called “not susceptible” rather than “nonsusceptible.”


interpretive criteria

minimal inhibitory concentration (MIC) or zone diameter value used to indicate susceptible, intermediate, and resistant; susceptible – a category that implies that an infection due to the strain may be appropriately treated with the dosage regimen of an antimicrobial agent recommended for that type of infection and infecting species, unless otherwise indicated; intermediate – a category that implies that an infection due to the isolate may be appropriately treated in body sites where the drugs are physiologically concentrated or when a high dosage of drug can be used; also indicates a “buffer zone” that should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations; resistant – resistant isolates are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules and/or fall in the range where specific microbial resistance mechanisms are likely (eg, β-lactamases), and clinical outcome has not been predictable in effectiveness studies.

Project: VET01


interpretive criteria

MIC or zone diameter value used to indicate susceptible, intermediate, and resistant as defined in M2—Performance Standards for Antimicrobial Disk Susceptibility Tests; M7—Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; and M11—Methods for Antimicrobial Susceptibility Testing of Anaerobic Bacteria

Project: VET02


interpretive criteria

minimal inhibitory concentration (MIC) or zone diameter value used to indicate susceptible, intermediate, and resistant as defined by the interpretive criteria.

Project: M39, M02, M07

For example, for antimicrobial X with interpretive criteria of:

MIC (µg/mL) Zone Diameter (mm)
Susceptible ≤ 4 ≥ 20
Intermediate 8–16 15–19
Resistant ≥ 32 ≤ 14
“Susceptible breakpoint” is 4 µg/mL or 20 mm. “Resistant breakpoint” is 32 µg/mL or 14 mm.


interstitial fluid

a liquid found between the cells of the body that provides much of the liquid environme