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.


3ʹ poly(A) tail

a sequence of adenylyl residues at the 3ʹ end of eukaryotic messenger RNA

Project: MM13

NOTE: Almost all mature eukaryotic messenger RNAs have 3ʹ 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 messenger RNA 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


5ʹ cap

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

Project: MM13

NOTE: It consists of a residue of 7-methylguanosine and a triphosphate bridge linking it 5ʹ-5ʹ to the end of the polynucleotide chain. The cap structure is thought to protect the 5ʹ end of the messenger RNA from degradation by phosphatases or nucleases and to facilitate initiation of translation of messenger RNA 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 amplicon that is, in turn, cleaved during the extension phase of the polymerase chain reaction 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

Alternate Term: leader sequence


5′-exonuclease assay

(hydrolysis probe assay) a nucleic acid assay that uses the 5′ to 3′ exonuclease activity of Thermus aquaticus (Taq) polymerase to cleave a dual-labeled probe annealed to a target sequence during amplification

Project: MM24

NOTE: The release of a fluorogenic tag from the 5′ end of the probe is proportional to the target sequence concentration.


A260/A280

the ratio of the absorbance of a nucleic acid solution at a wavelength of 260 nm divided by the absorbance of the same solution at a wavelength of 280 nm

Project: MM09, MM17

NOTE: Absorbance is a spectrophotometric method of assessing nucleic acid purity. DNA solutions with negligible contamination yield a ratio of ≥ 1.8, while RNA solutions with negligible contamination yield a ratio of ≥ 2.0.


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; 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


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 ultrafiltration measurement procedures (whether direct or indirect) typically fall into this category, since such calibrants are normally used either to measure the free thyroid hormone concentration in the dialysate in the first case, or the total concentration in the sample in the second case.


absolute relative difference

absolute value of the difference between a measurement and a reference value, expressed in percent of the reference value (reference value must be different from 0) (see equation in POCT05)

Project: POCT05


absorb

to take up or receive by chemical action; to take in and utilize

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

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, eg, A540HiCN = absorbance of hemiglobincyanide at 540 nm.


absorbance

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

Project: VET04, VET03

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.


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 chemically or physically in bulk by a material (absorbent) and held in pores or interstices in the interior

Project: GP40, NRSCL8

NOTE: See also adsorption, sorption.


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

(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


accelerated stability testing

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

Project: EP25, EP30

NOTE: Results from such studies may be used to compare the influence of product design/packaging factors or, in some cases, to estimate the expiry 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, PRE05, C62


acceptable risk

a state achieved in a measuring system in which 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 (whether perceived or real), patients, physicians, institutions, and society are willing to risk the consequences

Project: EP23, GP47


acceptance criteria

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

Project: AUTO13, MM21

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 3534-2)

Project: EP17, EP10, QMS24


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

a subsystem that consolidates data from one or more point-of-care devices 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, or an access point that is part of a multifunctional device such as a patient monitor or personal computer.


access point

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); or an access point can be part of more complex equipment, such as bedside patient monitors or personal desktop computers.


access point interface

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

Project: POCT01

NOTE: This definition is equivalent to IEEE “bedside communication controller.”


accession

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


accession

sequence of alphanumeric characters that uniquely identifies a specimen and the patient from whom it was derived in the information system that generates the sequence

Alternate Term: case ID

Project: AUTO14

NOTE: It is frequently referred to as the accession number or case number. A single patient might have many accession numbers associated with them, but an accession or case ID must only be associated with one patient at a single health care institution. Therefore, if a location prefix or site identifier is required to uniquely identify a specimen by its accession number within a multifacility health care system, the location prefix or site identifier is a required component of the accession or case ID.


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


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

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

procedure by which an authoritative organization gives formal recognition that an organization or person is competent to carry out specific tasks (modified from ISO/IEC 17000)

Project: MM19, MM22


accreditation

process by which an authoritative organization gives formal recognition that an organization (eg, a laboratory) is competent to carry out specific tasks

Project: QMS21, QMS25, QMS01, MM24, QMS17

Source: Quality Glossary


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)

Alternate Term: accuracy of measurement; measurement accuracy

Project: PRE04, ISO IEC Guide 99, H58, GP16, POCT05, I/LA20, C34, EP18, M55, POCT09, C43, M51, H26, NBS04, MM06, M24, I/LA28, GP34, H02, I/LA34, EP23, C58, MM19, NBS05, EP10, EP29, MM05, MM01, C56, EP31, EP27, MM20, MM14, EP09, EP26, C40, MM22, MM09, H60, EP14, C62, C57, MM03, MM23, POCT06, EP19, M52, C64, MM21, POCT14, H48, POCT04, QMS24, C24, NBS09, EP34, C63, C52, EP07, MM17, C49, MM24, H62, NBS10, MM26, M67

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: In nucleic acid sequence analysis, the overall accuracy refers to the closeness of the agreement between a test result (ie, derived assembled sequence) and the accepted reference value (ie, 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 antimicrobial susceptibility testing 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 assays, the US IgE Standard and the international immunoglobulin E standard (11/234) are available for use as primary reference materials to promote trueness; NOTE 11: For immunoglobulin E antibody assays of defined allergen specificity, there are currently no universally accepted immunoglobulin E antibody standards with calibrated levels of allergen-specific immunoglobulin E. Heterologous interpolation of allergen-specific immunoglobulin E antibody results from a total immunoglobulin E dose response curve has become a universally accepted calibration method. Over the years, several research-based secondary immunoglobulin E antibody standards have been prepared with mass per volume unit estimates using antibody adsorption or depletion methods; NOTE 12: 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 13: Due to their inherent limitations, immunoassays are expected to produce some false-positive and false-negative screening results, thus definitive testing is warranted; NOTE 14: Temporal accuracy is the combination of point and trend accuracy; NOTE 15: In practice, an accepted reference value is substituted for the true value (ISO 3534-2); NOTE 16: Accuracy refers to a combination of trueness and precision (ISO 3534-2); NOTE 17: See trueness.


accuracy

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

Project: POCT13, C48, POCT17


accuracy

(clinical or diagnostic) the qualitative or quantitative expression of a particular white blood cell 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

(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

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

Project: C44, C37, H44, ISO 15198, GP40, AUTO08, EP21, EP17, QMS23, POCT15

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 international normalized ratio values traceable to an International Reference Preparation (ISO 17593); NOTE 3: Usually expressed in the same units as the result, as the difference between the true value and the measured value, or as a percentage of the true value that the difference represents. Expressed this way, the quantity is more correctly termed “inaccuracy.”


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 set 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

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

Project: M50


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

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 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 fast

descriptive term for bacteria that resist decolorization with acid-alcohol due to the presence of mycolic acids

Project: M48


acid α-glucosidase

a lysosomal enzyme, encoded by the acid α-glucosidase 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


acquisition method

method of analysis for the mass spectrometer to acquire data

Project: NBS04, NBS09

NOTE: Three data acquisition methods are used in newborn screening: precursor ion scanning, selected reaction monitoring, 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 measuring 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


actionability

the ability of the test result to modify patient management

Project: MM26

NOTE: A variant is considered actionable if it is associated with a known targeted therapy, patient prognosis, or response to therapy.


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

a coagulation test that is particularly sensitive to abnormalities in the intrinsic blood coagulation pathway and the anticoagulant activity of heparin

Project: POCT14

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


activated partial thromboplastin time

a coagulation test that measures the time, in seconds, needed 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: POCT14, H21, H57

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


activated partial thromboplastin time test

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

NOTE: Activated partial thromboplastin time measures the intrinsic and common coagulation pathways


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

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


actor

information systems or components of information systems that produce, manage, or act on information associated with operational activities in the enterprise

Project: AUTO16


acute HIV infection

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

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: NBS09, NBS04

NOTE 1: The fatty acid attached to carnitine reflects the composition of fatty acids within the mitochondria and is typically between two and 26 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 NBS04, the acylcarnitine species are referred to by their acyl chain carbon lengths (eg, octanoylcarnitine is referred to as “C8”); NOTE 4: Throughout NBS09, the acylcarnitine species are referred to by their acyl chain carbon lengths (eg, lignoceric acid is referred to as C24:0, and cerotic acid is referred to as C26:0); NOTE 5: See carnitine.


adapter

a short sequence of deoxynucleotides used to couple segments of oligonucleotide

Alternate Term: oligonucleotide adapter

Project: MM09


addendum

information added as an attachment or supplement to a document or record that expands or clarifies the original document or record

Project: MM01, QMS26

Source: Quality Glossary

NOTE: An addended report does not change the original test result(s) or diagnosis.


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.


addendum

ancillary report with additional information that expands or clarifies the original final diagnosis but does not change it

Alternate Term: addenda

Project: QMS12

EXAMPLE: Adding information derived from additional diagnostic studies, recuts from specimen blocks, consultations.


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

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, GP42

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


adhesion

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

Project: H58


adjunctive continuous glucose monitoring

use of continuous glucose monitoring data to supplement, not substitute, self-monitoring blood glucose measurements in diabetes management

Project: POCT05


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 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)

Alternate Term: adjustment of a measuring system

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 gainadjustment) (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

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 to a special care baby unit (for all babies admitted from delivery or transfer) or within a short time after this admission and before the provision of treatments and interventions

Project: NBS03


adrenal insufficiency

a condition in which the adrenal glands do not produce adequate amounts of steroid hormones, primarily cortisol, but possibly also aldosterone (a mineralocorticoid), which regulates sodium conservation, potassium secretion, and water retention

Project: NBS09

NOTE: Because of the urinary losses of sodium, craving for salt or salty foods is common.


adsorb

to gather a gas, liquid, or dissolved substance on a surface in a condensed (usually monomolecular) layer

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. 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

a substance added to a specimen by a urine drug donor that will cause the specimen to test negative on initial screening

Project: C52, C63

NOTE 1: Use of adulterants to avoid detection in forensic testing is considered even more serious than drug abuse itself; NOTE 2: In pain management, the use of an adulterant in the form of the drug prescribed (in order to test positive) is also an issue.


Advanced Encryption Standard

a future Federal Information Processing Standards publication being developed by the National Institute of Standards and Technology to succeed the Data Encryption Standard. 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

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.)


adverse event

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

Project: QMS11

Source: Quality Glossary


adverse event

term for any harmful medical event that is not consistent with the desired, normal, or usual operation of the product/device

Project: EP19


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

the force of attraction between molecules

Project: I/LA30


affinity

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

Project: I/LA20, I/LA34

NOTE: Affinity is best measured using a monovalent antigen and a monovalent antibody 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 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

Alternate Term: purified chromatography

Project: I/LA29

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


affinity constant

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 plates that are inoculated with a bacterial suspension to determine the minimal inhibitory concentration

Project: VET05, 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.


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.


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, epinephrine, thrombin, arachidonic acid, ristocetin)

Project: H58


agreement

a contract, order, or understanding between two or more parties, such as between a laboratory and one of its vendors or customers

Source: Quality Glossary


agreement

the proportion of specimens in which 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 – the proportion of nonreference standard negative samples in which the new test is negative; positive percent agreement – 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, MM24


agreement

the proportion of specimens for which results obtained using a candidate specimen type and those obtained using a primary specimen type agree

Project: EP35


agreement

the proportion of specimens for which results obtained using a candidate examination and those obtained using comparative examination agree

Project: EP12

NOTE 1: Agreement can also be measured within an examination using the same subject population but across two factors such as operators, sites, instruments, or reagent lots; NOTE 2: See negative percent agreement and positive percent agreement.


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

a signal intended to call the user’s attention to the presence of a potentially hazardous condition

Project: POCT05


alarm threshold

a glucose concentration or glucose concentration rate of change that initiates an 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.


alert threshold

a glucose concentration or glucose concentration rate of change that initiates an alert

Project: POCT05


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.


aleurioconidium

(pl. aleurioconidia) a terminal or lateral conidium released by lysis or fracture of the supporting cell

Project: M54


algorithm

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

Project: MM17, I/LA28


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

process or set of rules to be followed in calculations or other problem-solving operations

Project: AUTO15

NOTE: Algorithms can perform calculation, data processing, and automated reasoning tasks.


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: MM09, MM18

NOTE 1: This assessment is made using pairwise or multiple-alignment algorithms; NOTE 2: Alignment algorithms can be global or local.


aliquot

a portion of a larger whole (eg, a smaller sample acquired from a primary sample)

Project: EP30

NOTE: The word “aliquot” is used to denote a smaller sample of a larger primary sample and is independent of the vessel type used for partitioning.


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

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, AUTO07, AUTO02, 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

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

Project: PRE05, C52, EP35

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


aliquot

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

Project: PRE04, AUTO14

NOTE 1: An aliquot removed from the primary (original) specimen container after initial processing, such as centrifugation, is considered chemically identical to all other subdivisions; NOTE 2: When a serum or plasma sample is analyzed, the aliquot may be a precisely measured volume or mass from which the measurand is quantified; NOTE 3: 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, and cerebrospinal fluid; NOTE 4: 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 can 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

Alternate Term: aliquot tube, daughter tube, derivative tube

Project: AUTO12, AUTO14

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 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: MM22, MM24

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.


allele

1) in genetics, any of several forms of a gene that is responsible for hereditary variation; 2) one of the alternate forms of a polymorphic DNA sequence that is not necessarily contained within a gene; 3) one of the alternative forms of a gene that may occupy a given locus

Project: MM09, MM10, MM12, MM01, I/LA29, MM17

NOTE: 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: MM03, NBS05

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


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

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


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: MM24


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 immunoglobulin E 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 immunoglobulin E 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 I/LA20, 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 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 immunoglobulin E antibodies in humans.


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 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 primarily responsible for immunoglobulin E antibody binding on the drug molecule

Project: I/LA34


allergenic epitope

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

Project: I/LA20


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 immunoglobulin E 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

Project: DI01


allogeneic

in immunology, cells, tissues, etc., that are related but sufficiently dissimilar in genotype to interact antigenically

Project: DI01


allogeneic

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


alloimmunization

the immunization of one animal with antigens from another of the same species

Project: DI01


allophycocyanin

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


allophycocyanin

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

Alternate Term: APC

Project: H43, H42

NOTE: Allophycocyanin 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 or diode laser.


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


allowable drift

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

Alternate Term: measurand drift

Project: EP25


allowable error limits

symmetrical tolerance, plus and minus, around the target value for an analyte

Project: EP23


allowable total analytical error

the amount of error in a measurement that can be tolerated without invalidating the medical usefulness of the result

Project: EP26

NOTE 1: Allowable total analytical error is an analytical quality goal that sets a limit for both the imprecision (ie, random error) and bias (ie, systematic error) that are tolerable in a single measurement or single test result; NOTE 2: Allowable total analytical error excludes pre- and postexamination errors; NOTE 3: Such criteria are estimated from the influence of error in a test result on clinical outcome, from defined medical requirements, from biological variation, or from analytical capability; NOTE 4: In EP26, allowable total analytical error is abbreviated “TEa” (total error allowable); other publications might use “ATE” (allowable total error); NOTE 5: “Analytical performance specification” is another term used for the allowable total analytical error.


allowable total error

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

Project: MM10, POCT14


allowable total error

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, EP07

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 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 quality control strategy; NOTE 3: Some publications denote allowable total error as “ATE”; NOTE 4: Also called “total error allowable.”


allowable total error

an analytical quality goal or limit that sets a maximum for the combined effects of all error components (ie, inaccuracy) including both imprecision (random error) and all systematic effects (including bias) that are tolerable in a single measurement or single test result

Project: EP10


allowable total error

analytical quality goal that sets a limit for the combined effects of all error components (ie, inaccuracy), including imprecision (random error) and all systematic effects (including bias) that are tolerable in a single measurement or single test result

Project: EP21


allowable total error zone

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

Project: EP27


alpha error

probability of falsely rejecting the null hypothesis when it is true

Alternate Term: type I error

Project: EP07, EP31

NOTE: See confidence level.


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.


altered biological matrix

milieu in which the analyte exists that has been modified or changed through additional processes not routinely conducted as part of the normal specimen collection process (eg, treatment with heat or sodium hydroxide, clarification of the specimen milieu by centrifugation)

Project: EP39


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

Source: Quality Glossary


alternative assessment

(proficiency testing) a system for determining the reliability of tests for which formal proficiency testing 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)


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

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.


amended report

change made to add or rephrase information, editorial changes, changes made to improve readability or clarity, or additional information that changes the final diagnosis or clarifies the original final diagnosis or interpretation

Project: QMS26, QMS12

Source: Quality Glossary

EXAMPLE: Amending a final surgical pathology diagnosis arising from a second review of the material.


American Standard Code for Information Interchange

(ASCII) a set of digital codes representing letters, numerals, and other symbols that is widely used as a standard format in the transfer of text between computers

Alternate Term: ASCII

Project: AUTO14

NOTE: ASCII is the required character representation to be used for CLSI AUTO14


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

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

Alternate Term: amplification product

Project: MM03, MM18, M55, MM19, MM22, MM24, NBS05

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


amplicon

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

Project: NBS06, MM16, MM17, POCT15

NOTE: Amplicons will be double-stranded DNA if created by polymerase chain reaction and will be primarily single-stranded RNA if created in a nucleic acid sequence-based amplification or transcription-mediated amplification reaction.


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: Polymerase chain reaction is a common method of nucleic acid 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 additional study

Project: MM18, MM24, POCT15

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


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 product

the relatively low molecular weight products created from a target amplification reaction

Alternate Term: amplicon

Project: MM10

NOTE: Amplicons will be double-stranded DNA if created by polymerase chain reaction and will be single-stranded RNA if created in a nucleic acid sequence-based amplification or transcription-mediated amplification 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 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: ISO 17511, ISO 18153, EP06, EP10, MM07, EP15, I/LA23, I/LA25, I/LA24, MM14, HS02, MM13, MM10, MM03, POCT07, H59, I/LA28, MM12, MM16, POCT04, C49, I/LA21, C50, EP12, H58, POCT05, MM11, H57, MM17, C34, EP18, GP34, I/LA34, EP23, C58, MM19, NBS05, POCT10, MM01, C56, MM20, EP26, MM22, H60, C62, C57, MM23, POCT06, EP19, M52, C64, GP47, H48, QMS24, I/LA20, EP34, NBS09, EP07, EP31, NBS04, NBS07, C63, EP30, EP32, MM24, EP39, H62, NBS10

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 (modified from 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: The chemical entity or substance that is intended to be measured; NOTE 7: Formerly in CLSI EP10, 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, are terms 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 FISH 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; NOTE 18: For the purpose of NBS04 and NBS09, see biomarker; NOTE 19: A related term is measurand; NOTE 20: This is the chemical entity/substance that is actually intended to be measured; NOTE 21: In the measurand “mass of total protein in 24-hour urine,” “total protein” is the analyte (and “mass” is the property). In “amount of substance concentration of glucose in plasma,” “glucose” is the analyte (and “amount of substance concentration” is the property); NOTE 22: In the case of analyte-detection, qualitative examinations, an analyte is a unit that can be counted such as “copies of a specified bacterium” for which the specified bacterium is the analyte; NOTE 23: In “amount of glucose in plasma,” “glucose” is the analyte and the long phrase represents the measurand; NOTE 24: The term “analyte” must not be used for “measurand.”


analyte

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

Project: ISO 18113-1, C24

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, POCT15


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

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 (modified from 21 CFR §864.4020)

Project: MM06


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 (21 CFR 864.4020)

Project: H43, I/LA28

NOTE 1: An analyte-specific reagent is the active ingredient of an in-house test; NOTE 2: Analyte-specific reagents 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 analyte-specific reagent 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. Analyte-specific reagents 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 analyte-specific reagent 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 analyte-specific reagent to be used for purposes of allergen-specific immunoglobulin E testing, to date most if not all existing test systems are configured in such a manner that precludes use of analyte-specific reagents. Of note, use of analyte-specific reagents 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 analyte-specific reagent, a “general purpose reagent” 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 analyte-specific reagents, general purpose reagents are not labeled for a specific clinical or diagnostic use. Because general purpose reagents are not analyte-specific, they should be able to be combined with, or used in conjunction with more than one analyte-specific reagent. In contrast, as stated above, an analyte-specific reagent is a specific chemical component, probe, or antibody that can detect an individual chemical substance or ligand. An analyte-specific reagent is considered the “active ingredient” or “building block” of a laboratory-developed test.


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

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, AUTO15

NOTE: See measuring interval.


analytical measurement range

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: H57, POCT09, EP31

NOTE: See measuring interval.


analytical measuring interval

set of values of quantities of the same kind that can be measured by a given measuring instrument or measuring system with specified instrumental measurement uncertainty, under defined conditions (JCGM 200:2012)

Alternate Term: working interval; measuring range; measuring interval; measurement interval

Project: I/LA21, ISO 18113-1, H26, POCT07, MM06, EP06, C51, EP17, C56, MM14, EP09, EP26, H60, VET04, C62, EP05, EP15, C57, MM03, MM23, POCT06, EP21, C24, EP34, C63, MM17, C34, C62, GP26, H26, EP39, EP35, NBS10

NOTE 1: In some fields, the term is “analytical measurement range,” “measuring range,” or “measurement range” (modified from JCGM 200:2012); NOTE 2: The lower limit of a measuring interval should not be confused with “detection limit” (JCGM 200:2012); NOTE 3: This represents the interval of in vitro diagnostic examination results over which the performance characteristics of the in vitro diagnostic medical device were validated by the manufacturer; NOTE 4: Formerly, the terms “reportable range” or “measuring range” were used in CLSI documents; NOTE 5: The measuring interval over which the performance characteristics of an in vitro diagnostic medical device have been validated has been called the reportable range (ISO 18113-1); NOTE 6: For a discussion of the difference between interval and range, see A.2.11 (ISO 18113-1); NOTE 7: In the United States, the term often used is “analytical measuring range”; NOTE 8: In laboratory medicine, the term is defined as “measuring range,” or “analytical measurement range”; NOTE 9: The measuring interval is intended to refer to the interval of values that a measurement procedure can directly measure on the sample without any dilution, concentration, or other pretreatment not part of the usual measurement process; NOTE 10: The measuring interval has been called the analytical measurement range, reportable range, analytical range, and calibration range; NOTE 11: For EP05, the range of values (in units appropriate for the measurand) over which the acceptability criteria for the measurement procedure have been met; ie, the intersection of the linearity interval, the interval limited by the lower and upper limits of quantitation, and the interval representing acceptable imprecision; NOTE 12: The interval (or range) of values (in units appropriate for the analyte [measurand]) over which the acceptability criteria for the measurement procedure have been met; that is, where errors due to nonlinearity, imprecision, or other sources are within defined limits; NOTE 13: Formerly, the term “reportable range” was used in EP15, and another commonly used term is “analytical measurement range”; NOTE 14: The concentration range of results for which the measurement procedure functions to meet its intended use; NOTE 15: Measuring interval is determined by linearity, accuracy, and limit of detection; NOTE 16: The analytical measuring interval is the concentration interval within which a given accuracy is achieved and a linear relationship between measurand values and the measurement procedure’s results is maintained with no preexamination dilution, concentration, or other pretreatment not part of the standard or routine measurement; NOTE 17: Although the terms “analytical measuring range” and “working interval” are commonly used instead of “analytical measuring interval,” their use is not encouraged; NOTE 18: This interval is separate from the extended measuring interval, within which preexamination dilutions are needed to obtain results; NOTE 19: It is sometimes called “analytical measurement range” or “measurement range,” 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; NOTE 20: The ability of a measurement procedure to detect small quantities of the analyte; NOTE 21: Analytical sensitivity is usually expressed as the “minimum detectable concentration” or “detection limit.”


analytical method

See and use measurement procedure

Project: I/LA21, I/LA23


analytical performance

the sum of all analytical attributes that might be important for a test method for which the measurand is used for a specific intended use

Project: EP19

NOTE: Performance characteristics usually include detection capability, specificity, and other parameters.


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, NBS09


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 reactivity

the capacity of an assay to detect several strains or serovars of a species, several species of a genus, or a similar grouping of closely related organisms or antibodies (Jacobson et al. Manual of Diagnostic Tests and Vaccines for Terrestrial Animals 2017)

Alternate Term: inclusivity

Project: MM17


analytical result

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

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, NBS09

NOTE: An analytical run usually consists of both quality control specimens and patient specimens. NOTE 2: 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: MM09, ISO 15193, M55, M53, MM19, MM20, MM14, MM07, MM22, MM03, MM23, MM21, POCT17, I/LA20, NBS09, C63, MM17, NBS05, MM24, NBS10

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: Sensitivity may depend on the value of the stimulus; NOTE 6: 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 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; NOTE 19: The ability of a measurement procedure to detect small quantities of the analyte; NOTE 20: In the context of NBS09, sensitivity refers to the signal intensity of the analyte being measured; NOTE 21: The ability of a measurement procedure to detect small quantities of the analyte; NOTE 22: Analytical sensitivity is usually expressed as the “minimum detectable concentration” or “detection limit”; NOTE 23: The sensitivity may depend on the value of the stimulus; NOTE 24: The sensitivity depends on the imprecision of the measurements of the sample.


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 ability to obtain positive results in concordance with the reference method. Analytical sensitivity describes the ability to detect very low concentrations of a given substance in a biological specimen and is often referred to as the limit of detection

Project: MM01


analytical sensitivity

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

Project: MM26

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: ISO 15193, MM01, MM20, MM07, MM22, MM21, POCT17, I/LA20, NBS09, MM17, EP39, NBS10

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 assays with single allergens, “one particular substance” would indicate the repertoire of allergen-specific immunoglobulin E to “one particular allergen molecule”; NOTE 6: In the previous editions of I/LA20, analytical specificity of immunoglobulin Edetecting assays was solely linked to the capability to selectively measure immunoglobulin E, instead of other immunoglobulin classes or subclasses (eg, immunoglobulin G, immunoglobulin M). This definition refers to the “antibody-related analytical specificity (selectivity)” of immunoglobulin Edetecting assays and is still an important definition for modern immunoassays; NOTE 7: Allergen molecules for quantifying allergen-specific immunoglobulin E will limit the detected immunoglobulin E 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 immunoglobulin E 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 immunoglobulin Edetecting assays; NOTE 8: The term “allergen-related analytical specificity (selectivity)” is particularly useful to understand and justify the concept of species-specific vs crossreactive immunoglobulin E 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), immunoglobulin E detection with these molecules might be helpful to identify risk-associated allergen-specific immunoglobulin E responses; NOTE 9: The ability of a measurement procedure to determine specifically the concentration of the target analyte in the presence of potentially interfering substances or factors in the sample matrix.


analytical specificity

ability of a test method to measure solely the measurand (ISO 17511)

Project: EP19

NOTE: Specificity has no numerical value in this context. 


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

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

Project: ISO 17511, H44, H56, I/LA21, C50, GP16, M55, I/LA28, M53, MM19, H60, MM23, C63, H62

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: Analytical specificity (selectivity) of a measurement procedure should not be confused with diagnostic specificity; NOTE 4: Analytical specificity (selectivity) 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 measurand (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 immunoglobulin E and shows no cross-reactivity of the antihuman immunoglobulin E reagent with other classes of human antibodies (eg, immunoglobulin G, immunoglobulin A, immunoglobulin M, and immunoglobulin D). Tests of reagent specificity shall demonstrate that the antibody being measured is immunoglobulin E and that it is specific for the allergen of interest based on soluble allergen inhibition studies. The specific immunoglobulin E 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 measurand (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 or comparative 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; NOTE 12: “Analytical specificity” is an older term; historically, the preferred term is “selectivity”; NOTE 13: For assays that rely on antibody-based detection systems, specificity is an antibody (or 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 14: Analytical specificity (selectivity) of a measurement procedure should not be confused with clinical specificity; NOTE 15: See selectivity.


analytical specificity

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

Project: I/LA21, I/LA23, MM10, I/LA02, MM12, I/LA29, MM24

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

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

Project: MM09, MM26

NOTE 1: For nucleic acid sequencing, “analytical specificity” refers to the test’s ability to differentiate the target sequence from other sequences that may be present (eg, pseudogenes); NOTE 2: 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


Analytical Work Order Step

a unit of work allocated from a work order, assigned to an analyzer, performed on a biological specimen, and producing observations characterizing this specimen

Project: AUTO16


analyzer

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

Project: AUTO01, EP12, AUTO02, POCT04

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


analyzer manager

a key Laboratory Analytical Workflow Profile actor that organizes and distributes workload across connected laboratory instruments and similar devices

Project: AUTO16

NOTE: Typically, the analyzer manager is a source for orders and patient specimen information. Examples of analyzer managers are laboratory information and middleware systems


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 skin and the needle entering the skin

Project: GP41, PRE02


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, MM02, MM10, MM12, MM22, MM24


annotation

process of assigning functional information such as sequence conservation and predicting the effect of a variant on protein structure and function to DNA variants

Project: MM26

NOTE 1: Based on known information regarding functionality, pathogenicity, or actionability, variants can be evaluated that contribute to classification; NOTE 2: The tasks of variant annotation, evaluation, classification, and interpretation are usually performed by variant analysts or scientists.


anode

a positively charged conductor by which electrons leave an electrical device

Project: GP28


ANSI

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

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

NOTE: In Automation, the Microsoft Windows American National Standards Institute 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. 33rd ed. Elsevier, Inc.; 2019)

Project: GP41, PRE02


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

Project: M38, M27, M44, M52, M11


antibiogram

the report generated by analysis of antimicrobial susceptibility test results (usually from a single health care facility) from a defined period of time that reflects the percentage of first isolates (per patient) of a given species or organism group that is susceptible to each of the antimicrobial agents routinely tested

Project: M39


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, M53

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


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

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 immunoglobulin G, immunoglobulin A, immunoglobulin D, and immunoglobulin E, or 10 for immunoglobulin M) 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

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

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

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

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 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 antigens to identify the antibody or antibodies

Project: I/LA33


antibody screen

the testing of serum or plasma with material expressing red blood cell antigens for detection of unexpected antibodies

Alternate Term: antibody detection

Project: I/LA33


anticoagulant

a natural or pharmacological agent that inhibits clotting of blood or plasma

Project: H58, MM17, H59


anticoagulant

an agent that prevents the coagulation of blood or blood products

Project: POL1/2, GP34, GP39, H56, POCT04, H21


anticoagulant

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

Project: H60, H48


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

Project: NBS06


antigen

any substance foreign to the body that evokes an immune response either alone or after forming a complex with a larger molecule (as a protein) and that is capable of binding with a product (as an antibody or T cell) of the immune response

Project: m53


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

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

Alternate Term: epitope

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

an antibody directed against human immunoglobulin and/or complement

Alternate Term: AHG phase

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-immunoglobulin G plus anticomplement) or monospecific (anti-immunoglobulin G or anticomplement).


antihuman globulin phase

testing step where the use of a secondary antibody, typically directed against human immunoglobulin G or complement component 3 molecules, detects bound immunoglobulin G or complement component 3 on red blood cells (patient, donor, or reagent); the secondary antibody binds to the cell-bound immunoglobulin G or complement component 3 that has attached to the red cell either in vivo or in vitro

Alternate Term: AHG phase

Project: I/LA33


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 (eg, beta-lactamases), and clinical efficacy has not been reliable in treatment studies

Project: 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; 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

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

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 (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.

2)  intermediate (I) – 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  lactams in urine) or when a higher than normal dosage of a drug can be used (eg,  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 (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 that fall in the range in which specific microbial resistance mechanisms (eg, -lactamases) are likely, and clinical efficacy of the agent against the isolate has not been reliably shown in treatment studies.

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. 

Project: M45


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


antimicrobial susceptibility testing

procedures used to determine the susceptibility of bacteria to a specific antimicrobial agent(s)

Project: M07, M02

Source: Microbiology Glossary

NOTE: There are two major testing types, disk diffusion and dilution (broth and agar).


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 animals or human beings that contains antibodies to one or more antigens of interest

Project: ILA18


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


antithrombin

(formerly antithrombin III) a plasma protein that, 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 therapy

Alternate Term: AVK plasma

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 clinical indication, nucleic acid template structure, specified technical characteristics, and specimen types

Project: MM09


application-specific settings

user-specified instrument settings based on mean fluorescence intensity, median fluorescence intensity, or geometric-mean fluorescence intensity target values using fluorescence reference particles to set up an instrument’s fluorescence detector voltages for a defined assay or application

Alternate Term: assay-specific settings

Project: H62


appraisal costs

costs associated with measuring, evaluating, or auditing products or services to ensure 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 curve) as applied to receiver operating characteristic curves, the area subtended by the receiver operating characteristic curve and bounded by the x-axis (false-positive fraction) and the y-axis (true-positive fraction)

Alternate Term: AUC

Project: I/LA21

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


area under the curve

the computed area (definite integral) under the concentration-time curve. Practically, it is a pharmacokinetic measure of total exposure of drug over a defined time interval or time-averaged concentration of drug in the body

Project: M23


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

Project: C12, C25


arterialization

increasing blood flow through capillaries to more closely resemble arterial blood

Project: GP42


arthrocentesis

aspiration of a joint

Project: H56


arthrocentesis fluid

joint fluid obtained from aspiration of a joint

Project: H56


arthroconidium

(pl. arthroconidia) spore formed by disarticulation from a hypha at the point of a septation; often rectangular or barrel-shaped

Project: M54


artifact

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

Project: MM09


artificial analyte

component created or manufactured for use in spiking surrogate samples, with the intention of emulating the characteristic of the human specimen that will be measured or detected

Project: EP39

EXAMPLES: Synthesized chemical compounds, plasmid or cell-line DNA, transcript RNA, recombinant protein, cell culture used to reproduce an artificially created organism.


artificial matrix

milieu that is created or manufactured with the intention of emulating the specimen biological matrix

Project: EP39

EXAMPLES: Collection media, elution media, isotonic solutions, human or bovine serum albumin dissolved in buffer.


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

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; 5) quantitative assay - generates a spectrum of signal responses that correlate with the concentration of the analyte of interest; 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)

Project: DI01, I/LA18, I/LA23, I/LA33, MM22, MM24

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; NOTE 3: If the analyte preparations with known concentrations are available for calibration, the actual concentration of the analyte can be determined; NOTE 4: For the purpose of this document, assay is also known as the measurement procedure (see the definition in this section); NOTE 5: A qualitative assay reports only the presence or absence of the analyte, without quantification; NOTE 6: For the purpose of MM22 and MM24, assay is also known as the measurement procedure.


assay

See measurement procedure

Project: EP05


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 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)


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 quality control material

control materials with assigned analyte values provided by the manufacturer

Project: EP23


assembly

the tube and the closure

Project: GP39


assembly

the process of constructing sequences containing overlapping regions

Project: MM09, MM18

NOTE: This process is generally performed to generate a consensus sequence if multiple sequencing reactions are performed on a single amplicon.


assessment

systematic process to collect and analyze data to determine the current, historical, or projected status of an organization, person, process, or project

Project: QMS06, QMS01

Source: Quality Glossary

NOTE: Siebels DL, "The Quality Improvement Glossary"


assessment

(of target condition [TC]) the best available method for assessing the TC

Project: EP12

NOTE 1: Referred to as clinical reference standard in Standards for Reporting of Diagnostic Accuracy Studies (STARD); NOTE 2: The classification by this method is seen as a true binary determination; NOTE 3: May be a method developed through clinical consensus that determines whether a specimen is from an individual with or without the TC; NOTE 4: For analyte-detection examinations, the determination may be made, for example, by a composite reference method that includes multiple tests and/or methods and an algorithm for combining their results into a binary categorization.


assessor

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

Project: QMS17

Source: Quality Glossary

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


asset

any resource both available and useful during disaster response

Project: GP36


asset

single object in the laboratory containing a specimen or derivative of a specimen from a single patient 

Project: AUTO14

NOTE: A single asset typically has one but can have multiple bar codes, which are either etched or applied using labels. Each bar code with its associated human-readable information should represent the unique specimen on which it is applied or etched


asset key

single unique identifier for a single object in the laboratory

Project: AUTO14

NOTE: This single object can be a single specimen, block, slide, tube, aliquot, document, or other object representing something about or from a single patient 


assigned value

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

Project: QMS24


assigned value

value attributed to a particular quantity and accepted, sometimes by convention, as having an uncertainty appropriate for a given purpose

Project: EP10


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, AUTO07, AUTO02, 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

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


atomic mass unit

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

Project: NBS04, NBS09

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

Project: I/LA34


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−mediated food allergies)

Project: I/LA20

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


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


audit

systematic, independent, and documented process to obtain and evaluate evidence objectively to determine the extent to which specified criteria are fulfilled (modified from ISO 9000, ISO 19011)

Project: QMS06, QMS15, QMS16, QMS21, QMS01, QMS17

Source: Quality Glossary


audit conclusion

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


audit criteria

set of policies, procedures, or requirements used as a reference (modified from ISO 9000, ISO 19011)

Project: QMS15


audit evidence

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


audit plan

description of the activities and arrangements for an audit (ISO 9000, ISO 19011)

Project: QMS15


audit program

set of activities to identify internal audits and auditors, train auditors, and schedule and conduct internal audits

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, ISO 19011)

Project: QMS15


audit team

one or more auditors conducting an audit, supported if needed by technical experts (modified from ISO 9000, ISO 19011)

Project: QMS15


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


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


auditee

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

Project: QMS15


auditor

person with the competence to conduct an audit (modified from ISO 9000, ISO 19011)

Project: QMS15


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 identification and a unique password (what the user knows), security token (what the user has), or biometrics (who the user is).


authenticator

role played by a laboratory clinical expert when performing clinical validation of a set of results issued in a Clinical Document Architecture Release 2 laboratory report, by which this person authenticates and endorses the laboratory report or a subset of it

Project: AUTO16


authorization

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

Project: POCT12, 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 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)

Project: DL01


autochthonous

(autologous) derived from the subject itself

Project: DI01


autochthonous

describes a microorganism that is indigenous to a specific environment

Project: M56


autocontrol

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

Project: I/LA33


autofluorescence

the intrinsic fluorescence of unstained cells, generally caused by pyrimidines and flavin nucleotides

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 red blood cells is significantly lower than that of white blood cells, and instrument settings may need to be adjusted accordingly.


autofluorescence

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

Project: I/LA24


autograft

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

Project: DI01


autoimmunization

the process of becoming immune against constituents of one’s own cells, tissue, or components thereof

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, hospital information system, and/or laboratory automation system, 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


automated system

a system that may be fully automated or semiautomated

Project: I/LA33


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: I/LA33

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, laboratory automation systems, hospital information systems, 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 can connect and operate input-output units, automated analyzers, and other task-targeted devices such as aliquotters, centrifuges, and storage units). These automation systems might be operated by or have interfaces to hospital information systems, laboratory information systems, and laboratory automation systems. 

Project: AUTO12, AUTO14

NOTE: See laboratory automation system and laboratory information system


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, MM24

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, NBS09

NOTE: In NBS04 and NBS09, 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: AUTO10, AUTO15

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.


autoverification

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 laboratory staff

Project: EP33

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


autoverification parameter (table)

a listing of the causes (eg, results, flags, alerts) and effects (eg, rerun, reflex, addition of text) of specific details for a given algorithm

Project: AUTO15


autoverification rate

usually expressed as a percentage, the number of results that are sent directly to the patient record without human intervention to review the data before being sent out. This should be measured by analyte and not by patient

Project: AUTO15


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.


avidity

net affinity of all binding sites of antibodies

Project: I/LA30


avidity

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

Project: NRSCL8, I/LA23, 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.


avidity

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

Project: I/LA28


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


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


background

any signal that is measured but does not originate from the parameter of interest

Project: H62

NOTE: In flow cytometry, instrument background refers to the contribution of the signal produced by background light.


backsplash

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

Project: QMS04


backup

a copy of computer data

Project: QMS22

NOTE: A backup may be in the form of a file or the contents of a computer hard drive.


bacteremia

the presence of bacteria in the bloodstream

Project: M47


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 scorecard

a management tool that provides feedback on both internal business processes and external outcomes to continuously improve strategic performance and results

Project: QMS12

Source: Quality Glossary


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, AUTO07, AUTO02, AUTO03, I/LA33, 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 content construction software

the software that constructs the CLSI AUTO14-compliant content string from specimen ID information in the health care application or database according to the specifications set forth in Chapter 4.

Project: AUTO14


bar code content utilization software

software within a health care application that parses the content received from a decoded bar code, verifies the compliance of its format, and subsequently determines if the data within the bar code content exactly matches the correct unique specimen, aliquot or asset that has already been entered into the health care application

Project: AUTO14


bar code density

the density of a bar code symbol, whether linear or two-dimensional, refers to the space efficiency with which that particular symbol encodes data

Project: AUTO14

NOTE 1: High-density linear symbols use a smaller width of the narrow bar/space (element) than low-density linear symbols. Similarly, high-density two-dimensional symbols use smaller cells (dark/light) than low-density two-dimensional symbols. Regardless of symbol density, it is important to test the symbol with every bar code reader (handheld or fixed-mounted) that will be required to decode that symbol to establish compatibility of symbol density to bar code reader resolution; NOTE 2: Density is customarily expressed by the nominal width dimension of the narrow element in linear bar code symbols and the cell in two-dimensional bar code symbols. The unit of measure varies regionally but is typically either mil (0.001 inch) or millimeter. This dimension is typically referred to as the “X-Dimension.”


bar code module

the smallest individual element in a bar code

Project: AUTO14

NOTE 1: In a linear bar code, a module is the narrowest element (bar or space) in a bar code; NOTE 2: In a two-dimensional bar code, a module is the smallest rectangular or square element (cell) in the bar code. Both linear and two-dimensional bar codes are constructed of multiple modules of the same or different widths (see X-dimension)


bar code reader

any device used to "read" (also decode) a bar code symbol

Project: AUTO14

NOTE: Most devices used to decode two-dimensional symbols use camera-based technology


bar code system

a group of components, such as reading devices, printers, labels or applicators, and software, designed to use bar codes to facilitate the automatic collection of data, tracking, and the subsequent generation of useful output (reports, summaries, etc.)

Project: AUTO14


bar code, linear (one-dimensional)

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; 3) an ID code consisting of a pattern of vertical bars whose width and spacing identifies the item marked

Project: AUTO14

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


bar code, two-dimensional

a graphical image that stores information both horizontally and vertically

Project: AUTO14

NOTE: As a result of that construction, two-dimensional codes can store significantly more data than is possible with the capacity of a linear bar code


bar length

the length of the bars in the bar code

Project: AUTO01, AUTO07, AUTO02, AUTO12


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: MM10, MM18, MM09, MM24

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 partial pressure of carbon dioxide of 40 mmHg (5.3 kPa) at 37°C

Alternate Term: in vitro base excess, cBE(B), (BEvt)

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 partial pressure of carbon dioxide at 40 mmHg and at 37°C, 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 partial pressure of carbon dioxide of 40 mmHg (5.3 kPa) at 37°C

Alternate Term: in vivo base excess, cBE(ecf), (Bevv)

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.


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 is termed 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 convention for 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

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 local alignment search tool

pairwise alignment algorithm that aligns two sequences

Project: MM18

NOTE 1: Basic local alignment search tool is an open source tool for sequence alignment; therefore, it can be used by many database providers; NOTE 2: Basic local alignment search tool uses a scoring matrix to generate the best possible local alignment between two sequences.


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


basket trial

a clinical trial that tests how well a new drug or other substance works in patients who have different types of cancer but have the same variant or biomarker

Alternate Term: bucket trial

Project: MM26

NOTE 1: In basket trials, patients receive the same treatment targeting the specific variant or biomarker found in their cancer type; NOTE 2: Basket trials can enable new drugs to be tested and approved more quickly than traditional clinical trials; NOTE 3: Basket trials can also be useful for studying rare types of cancers and cancers with rare genetic changes; NOTE 4: Also known as a bucket trial.


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)

Alternate Term: lot

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

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)

Alternate Term: lot number

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.


battery

a set of one or more laboratory tests, identified by a single name and code that can be ordered to a laboratory

Project: AUTO16


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

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

Alternate Term: B lymphocytes

Project: NBS07, NBS06

NOTE 1: Normal B-cells can be transformed into continuous cell lines by the Epstein-Barr virus. NOTE 2: 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


bedside communication controller

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

Project: POCT01

NOTE: This is an IEEE definition, equivalent to “access point interface.”


bedside testing

See point-of-care testing

Alternate Term: point-of-care testing; near-patient 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, QMS12

Source: Quality Glossary


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


benign variant

a DNA sequence that is not associated with clinically recognized disease

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 not rejecting the null hypothesis when it is false

Alternate Term: type II error

Project: EP07

NOTE: See power.


beta error

probability of falsely rejecting the alternative hypothesis when it is true

Project: EP31


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

Project: POL1/2


beta-actin (ACTB) gene

the human gene for a nonmuscle cytoskeletal actin isoform

Alternate Term: actin

Project: NBS06

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


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.


between-unit homogeneity

unit-to-unit variation of a property of a reference material

Project: EP30

NOTE: The term “between-unit homogeneity” applies to all types of packages (eg, vials) and other physical shapes and test pieces.


bias

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

Alternate Term: measurement bias

Project: EP12, ISO IEC Guide 99, EP25, EP18, C43, H26, NBS04, MM06, H02, EP23, EP06, EP29, C56, EP27, EP26, C40, MM22, EP14, EP15, POCT13, EP19, MM21, QMS24, C24, NBS09, EP07, EP34, H48, MM10, C49, MM24, NBS05, NBS10

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 EP19, the metrological term “bias” is equivalent to the term “systematic difference”; NOTE 3: Difference between the expectation of a test result or measurement result and a true value; NOTE 4: In practice the accepted reference value is substituted for the true value; NOTE 5: Bias represents the quantitative expression of trueness; NOTE 6: 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 7: Bias at a specified concentration can be determined using the slope and intercept from a measurement procedure comparison regression; NOTE 8: In laboratory verification comparison studies using difference plots, when bias is relatively constant and in the same direction (positive or negative) within a specified measuring interval, bias can be expressed as an average over that specified interval; NOTE 9: The bias of a measuring instrument is normally estimated by averaging the error of indication over an appropriate number of repeated measurements; NOTE 10: The bias is the difference between the expectation of the test results and an accepted reference value (modified from ISO 5725-1); NOTE 11: The “accepted reference value” in Chapter 5 is the result from the same measurement procedure in the absence of the potentially interfering substance. In Chapter 7, it is the result from the comparative measurement procedure (ISO 5725-1); NOTE 12: See trueness; NOTE 13: When a value is obtained using a method other than a reference test method, the difference between biases of the methods is called a systematic difference. For simplicity, EP19 uses the term “bias” to refer to both situations; NOTE 14: For a qualitative, binary examination, bias is typically determined at the cutoff and expressed in terms of the instrument’s internal continuous response; NOTE 15: The difference between the expectation of the test results and an accepted reference value (modified from ISO 5725-1).


bias

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

Project: ISO 15197, ISO 17593, ISO 15198, ISO 5725-1, EP17, I/LA23, C58, C48, ISO 3534-1, ISO DIS 17593, MM12, H20, C50, H57, H26, GP34, MM20, H60, C57, POCT06, EP31, EP35

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); 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; 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; NOTE 6: Bias applies to quantitative measurement procedures; NOTE 7: In the context of EP35, bias refers to the estimated bias at specific concentrations from a measurement procedure equivalence study; NOTE 8: In EP35, the metrological term systematic difference is related to the term “bias.”


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

(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

any systemic error in measurements provided by a measurement procedure or system. Often associated with the average error across a sample of measurement/reference pairs

Project: POCT05


bias

(of measurement) difference between the expectation of the test results and an accepted reference value (ISO 5725-1); estimate of a systematic measurement error (JCGM 200:2012)

Project: EP09

NOTE 1: 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: Bias at a specified concentration can be determined using the slope and intercept from a measurement procedure comparison regression; NOTE 3: In laboratory verification comparison studies using difference plots, when bias is relatively constant and in the same direction (positive or negative) within a specified measuring interval, bias can be expressed as an average over that specified interval.


bias

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

Project: EP21, EP10, C62, POCT15

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; NOTE 3: Bias is the numerical counterpart of trueness.


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: POCT14, 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.

intermeasurement 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

the difference between the expectation of the measurement procedure results and an accepted reference value (modified from ISO 3534-2)

Project: EP33


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

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

Project: NRSCL8


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).


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, quality control, 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)

Project: POCT02


bidirectional interface

a parallel interface that can transfer data in both directions; for example, the transfer of information from the laboratory information system or Blood Establishment Computer Software to the automated system and from the automated system back to the laboratory information system or Blood Establishment Computer Software

Project: I/LA33

NOTE: See interface.


binary output

examination results that are reported as positive or negative, yes or no, or target condition present or absent

Project: EP12-IG


binding capacity

in Immunology, the capacity of a receptor, such as an antibody, to bind a ligand, such as an antigen

Project: DI01


binding capacity

within the context of I/LA20 and I/LA34, 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/LA34, 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.


biobank

storage system for biological material (blood, tissue, or other) for the purpose of future scientific investigation, and traceable to the individual from whom it originates

Project: PRE04


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: AST02, HS02, POCT10, POCT04


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).


bioinformatic pipeline

a series of software algorithms that process raw sequencing data and generate interpretations from the data

Project: MM26


bioinformatician

an expert who combines research in biology, medicine, and health-related studies with information technology to interpret data covering fields such as genetics

Project: MM26

NOTE: Bioinformaticians create and maintain databases of biological information and develop and use mathematical models for arithmetical analysis.


biologic

a drug that is prepared using a biological starting or source material (ie, 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 analyte

analyte composed of or derived from a specimen for use in spiking surrogate samples

Project: EP39

EXAMPLES: Analyte-positive specimens; purified or extracted protein; DNA extracted from formalin-fixed, paraffin-embedded tissue specimens; analyte obtained from purified organisms; biological analyte reproduced from cell culture.


biological matrix

components of a material system, except the analyte (modified from ISO 17511)

Project: EP39

NOTE: The biological matrix is the milieu in which the analyte exists in a given sample (eg, serum, urine).


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, ISO 18113-1)

Alternate Term: reference interval

Project: ISO 15189, I/LA02, ISO 18113-1, EP39, NBS10

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 15189, 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 15189, 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 and the upper reference limit of the reference population; NOTE 7: For genomic copy number microarrays, the range of copy number variants and absence of heterozygosity that occur in the normal healthy population. Also see reference range; NOTE 8: 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 enables relating the reference interval to age, sex, and ethnicity of the reference population, as appropriate; NOTE 9: The term “reference interval” is preferred over “reference range”; the latter term should be used to refer only to the difference between the upper and lower limits of an interval; 


biological reference interval

interval between, and including, the lower reference value limit and the upper reference value limit of the biological reference population

Alternate Term: reference interval

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

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; 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 population

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

Alternate Term: reference population

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)

Alternate Term: biosafety

Project: M29


biological safety cabinet

hood designed specifically to contain microorganisms

Alternate Term: biosafety cabinet

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–filtered laminar airflow for product protection, and high-efficiency particulate air–filtered exhausted air for environmental protection

Alternate Term: biosafety cabinet

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

Alternate Term: biosafety level

Project: M29, GP36


biological select agents and toxins

See select agent

Alternate Term: 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

Alternate Term: Category B, biological substance

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 (intraindividual) and between-subject (interindividual, group) variation

Project: EP33


biomarker

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

Project: MM13, MM23


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.


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, NBS09

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: A chemical entity that can be quantitated and in which there is a relationship between the amount of that entity and some pathogenic, pharmacological, or therapeutic event; NOTE 4: See primary markers and secondary markers.


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)

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

Alternate Term: biological safety

Project: M29


biosafety cabinet

See biological safety cabinet

Alternate Term: 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

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

Alternate Term: biological safety level

Project: M29, GP36


biosafety level 1

(Canadian, containment level 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

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

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

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

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 biosafety level 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

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

(Canadian, containment level 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

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

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 molecule that can be covalently attached to lysine residues of proteins

Project: NRSCL8

NOTE: This property is used in many detection systems.


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.


biphasic blood culture system

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

Project: M47


birth prevalence

the number of times a congenital disease is confirmed in a baby, as a fraction of the number of babies born alive

Project: NBS10

Source: Newborn Screening Glossary

NOTE 1: “Incidence” is not the same as “birth prevalence,” because incidence refers to the occurrences of a disease over time; NOTE 2: “Birth prevalence” should not be confused with “prevalence,” which is a measure of the total number of existing cases of a disease or condition as a fraction of a defined population.


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 H58, in most cases, this is platelet-poor plasma.


blank

(nontemplate control) 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, MM24


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)

Alternate Term: background indication

Project: ISO IEC Guide 99


blastoconidium

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

Project: M54


blind subculture

subculture 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

Alternate Term: masking

Project: 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

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

(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

(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

Alternate Term: venous blood specimen

Project: ISO CD 17593


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

Alternate Term: capillary blood specimen

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

the circulating intravascular tissue of the body, consisting of suspended formed elements and fluid plasma

Project: ISO 17593, POCT04

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


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

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

Project: H21


blood culture

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

Project: M47

NOTE: A single blood culture specimen may be divided or distributed into more than one bottle or tube.


blood culture series

a group of temporally related blood cultures that are obtained 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

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: I/LA33

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 laboratory information system can be interpreted to mean Blood Establishment Computer Software, 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

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

(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: POCT13, POCT17


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: POCT13, POCT17


blood specimen

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

Project: POCT13, POCT17


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: POCT14, POCT13, POCT17

NOTE: Arterial blood is obtained by arterial puncture or from an individual arterial line, catheter, or extracorporeal circuit. Capillary blood is obtained by capillary puncture; the most commonly used capillary collection site is the finger. Venous blood is obtained by venipuncture or from an indwelling line or catheter.


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


bloodborne pathogens

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

Project: X3, M29

NOTE: These pathogens include, but are not limited to, hepatitis B virus, hepatitis C virus, and HIV.


bloodstream infection

an infection associated with bacteremia or fungemia

Project: M47


body fluid testing

measurement of measurand(s) in biological specimens for which no performance claims from the measurement procedure’s manufacturer are available

Project: C49


bone alkaline phosphatase

an enzyme found in osteoblasts

Alternate Term: bone ALP

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)

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


borderline result

a term sometimes used for an out-of-range screening result that is close to a program-established screen-positive cutoff value and that indicates moderate risk/possible disease, rather than high risk/probable disease

Project: NBS02, NBS10

Source: Newborn Screening Glossary

NOTE 1: A screen-positive result in the borderline range is typically followed up with a request for an additional screening specimen, rather than diagnostic testing or clinical evaluation; NOTE 2: Follow-up actions for a borderline result usually take additional time and should be restricted to diseases for which diagnosis and treatment are not time critical; NOTE 3: When a borderline result is obtained for the second time, the patient might be referred for diagnostic testing and/or clinical evaluation, rather than specimen collection for another screen; NOTE 4: See screen positive and repeat screening (requested); NOTE 5: In CLSI NBS10, see Figures 1 and 2.


bottom of cap

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

Project: AUTO01, AUTO07, AUTO02, AUTO12

NOTE: This point may be inside the tube.


bottom of container

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

Alternate Term: bottom of tube

Project: AUTO01, AUTO07, AUTO02, AUTO12


bottom of tube

See bottom of container

Project: AUTO02, AUTO12


bound fraction

the fraction of total analyte bound to receptor

Project: LA01


bound ratio

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

Alternate Term: free ratio, bound fraction, free fraction

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

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

Project: M38

NOTE 1: Minimal inhibitory concentration 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 or zone diameter value used to categorize an organism as susceptible, susceptible-dose dependent, intermediate, or resistant

Project: VET09

NOTE 1: In CLSI VET09, “breakpoints” refers to clinical breakpoints, which is the phrase used in some jurisdictions to refer to thresholds used to categorize bacterial isolates in terms of clinical predictions; NOTE 2: Breakpoints are only approved for treatment or control purposes; NOTE 3: See interpretive category (for breakpoints), control//metaphylaxis, and treatment.


breakpoint

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

Project: M24, M11

NOTE 1: MIC or zone diameter values generated by a susceptibility test can be interpreted based on established breakpoints; NOTE 2: See interpretive category (for breakpoints); NOTE 3: Also known as a "clinical breakpoint"


breakpoint

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

Project: M39, VET02, M02, M07, M23, VET01, M44

Source: Microbiology Glossary

NOTE 1: Minimal inhibitory concentration or zone diameter values generated by a susceptibility test can be interpreted based on established breakpoints; NOTE 2: See interpretive category (for breakpoints); NOTE 3: Also known as “clinical breakpoint”; NOTE 4: Because breakpoints are largely based on pharmacologically and clinically rich datasets using in vitro and in vivo data, they are considered robust predictors of likely clinical outcome.


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

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 (eg, an abscess) that has not been drained adequately.


brefeldin A

a relatively nontoxic but potent protein inhibitor of intracellular protein transport

Project: I/LA26


British thermal unit

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 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 into a liquid nutrient medium that are inoculated with a bacterial suspension to determine the minimal inhibitory concentration of the antimicrobial agent

Project: VET02

NOTE: When this procedure is performed in test tubes, it is referred to as broth macrodilution; when performed in microdilution plates, it is called broth microdilution.


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

the fraction of a centrifuged blood sample that contains most of the white blood cells

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).


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.


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


C5

value in a relevant scale (eg, an internal continuous response) where a binary examination declares a sample to be positive 5% of the time

Project: EP12, EP12-IG

NOTE: Like precision, C5 is associated with stipulated precision conditions.


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


C95

value in a relevant scale (eg, an internal continuous response) where a binary examination declares a sample to be positive 95% of the time

Project: EP12, EP12-IG

NOTE: Like precision, C95 is associated with stipulated precision conditions.


CA membrane

a reverse osmosis membrane constructed of cellulose diacetate/triacetate

Project: GP40


calcium ion-selective membrane

the active element of the ion-selective membrane 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

three levels of calibrated immunoglobulin E 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 immunoglobulin E antibody assays that are calibrated with a heterologous serum immunoglobulin E 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 immunoglobulin E assay but which are not commercially available for immunoglobulin E 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

the proposed three levels of calibrated immunoglobulin E 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 immunoglobulin E antibody assays that are calibrated with a heterologous serum immunoglobulin E 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 immunoglobulin E assay but which are not commercially available for immunoglobulin E 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

two levels of calibrated immunoglobulin E 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 immunoglobulin E antibody assays that are calibrated with a heterologous serum immunoglobulin E dose-response curve and which generate reliable, reproducible results; these assays behave consistently with respect to parallelism

Project: I/LA34


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: ISO IEC Guide 99, ILA29, H58, EP25, POCT09, ISO 18113-1, H26, H59, M53, C58, MM19, MM01, EP27, MM20, EP26, C40, MM22, EP14, C62, C57, MM23, POCT06, EP19, H54, POCT14, H44, EP10, MM12, POCT04, H47, H57, GP40, EP33, H48, EP34, EP31, C63, MM24

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; NOTE 5: The relationship of the sensor glucose measurement should be established to a biological medium; 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; NOTE 7: Calibration process is performed to meet accuracy claims; 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; NOTE 13: Calibration establishes the relationship between equipment or instrument response and the corresponding predetermined concentration or activity values of an analyte; NOTE 14: According to the US Code of Federal Regulations, calibration is the 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; NOTE 15: According to published regulations, calibration is the 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).


calibration

provision of a measurement system with a contemporaneous value of the same analyte made by a different (reference) method, intended to bring the measurement system’s reported values into better agreement with those of the reference method

Project: POCT05


calibration

process of assessing (and adjusting if necessary) the critical outputs of an instrument to a calibrator of a known value before performing laboratory work

Project: H26, H44, POCT13, POCT17, H62

NOTE 1: 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); NOTE 2: Comparison of a measurement instrument or system of unverified accuracy with a measurement instrument or system of known accuracy to detect any variation from the required performance specification.


calibration

comparison of a measurement instrument or system of unverified accuracy to a measurement instrument or system of known accuracy to detect any variation from the required performance specification

Project: QMS07, QMS13, QMS23, QMS24, QMS01

Source: Quality Glossary


calibration curve

expression of the relation between indication and corresponding measured quantity value (JCGM 200:2012)

Project: ISO IEC Guide 99, MM19, H48

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, EP32

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 practical realization, 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); NOTE 5: Traceability chain is synonymous with calibration hierarchy.


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 a product 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 international normalized ratio 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

Alternate Term: calibrator

Project: NRSCL08, QMS24, H62

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 should be traceable to a national or international reference preparation or reference material when these are available; NOTE 7: Quantitative fluorescence calibrators can be spectrally matched or differ in spectral properties. Although the spectrally matched calibrator is superior, especially for probes with pH sensitivities, the equivalent reference fluorophores method for calibrators provides an alternative for fluorochromes lacking National Institute of Standards and Technology traceable material or standard reference material; NOTE 8: See equivalent reference fluorophores and standard reference material.


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, I/LA34

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 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 to measurand concentration

Project: C40

NOTE: There is no International Organization for Standardization (ISO) term for "calibration standard." In ISO terminology, it would be called a “reference material” used for calibration. See reference material.


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

Alternate Term: transfer protocol

Project: ISO 17511, EP32


calibration verification

the assaying of calibration materials in the same manner as patient samples to confirm that the calibration of the instrument, kit, or test system has remained stable throughout the measurement range for patient test results

Project: QMS13, QMS23, MM06, POCT04, POCT09, H26, QMS01

Source: Quality Glossary

NOTE: US CFR 493.2


calibrator

measurement standard used in calibration (JCGM 200:2012)

Project: ISO IEC Guide 99, C34, H26, MM06, NBS05, C40, H48, POCT04, QMS24, I/LA20, H62, NBS10

NOTE 1: The term “calibrator” is only used in certain fields (JCGM 200:2012); NOTE 2: 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 within limits established during its preparation; 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; NOTE 7: A calibration material may be used for all measurement procedures or restricted to some within limits established during its preparation; NOTE 8: Calibrators can be used internal (within the same tube) or external (in another tube) to the specimen. In such cases, within MM06, they are referred to as internal calibrators or external calibrators.


calibrator

measurement standard used in the calibration of an IVD instrument or system (adapted from JCGM 200:2012)

Project: ISO 18113-1


calibrator

reference material whose value is used for the independent variable in a calibration function (ISO 17511)

Alternate Term: calibration material

Project: ISO 17511, I/LA23, QMS23


calibrator

substance, material, or article intended to be used in the calibration of an in vitro diagnostic medical device (modified from EN 375)

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


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

NOTE: 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.


calibrator

See calibration material

Project: I/LA34


calibrator

substance, material, or article intended by its manufacturer to be used to establish the measurement relationships of an in vitro diagnostic medical device

Project: EP31


calorie

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

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


candidate reagent lot

any reagent lot about to be used for the first time in a specific medical laboratory

Project: EP26


candidate specimen

the specimen that is being assessed or evaluated for the purpose of establishing suitability

Project: EP35

NOTE: In EP35, the term “candidate specimen” is used for assessing equivalence between two specimen types.


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

Alternate Term: capillarity

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

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 puncture

the collection of blood using a minimally invasive lancet or puncture device

Project: POCT14

NOTE: The most commonly used site to collect blood by capillary puncture for point-of-care coagulation testing is the finger.


capillary puncture device

a single-use device that punctures or cuts the skin with a sharp pointed or bladed instrument that automatically retracts into a protective housing

Project: GP42


capillary tube

a hollow cylindroid of sufficiently narrow internal diameter such that it brings about capillary action when its tip is placed in a fluid specimen

Project: GP42

NOTE: A capillary tube is also known as a capillary straw.


capsule

a mucopolysaccharide material surrounding a cell wall

Project: M54


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


Carba NP test

colorimetric microtube assay for detecting carbapenemase production

Project: M02, M07, VET01

Source: Microbiology Glossary


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

Alternate Term: CO2

Project: NRSCL8


carboxyfluorescein succinimidyl ester

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, carboxyfluorescein succinimidyl ester measurements have been used as a marker of proliferation; NOTE 3: Carboxyfluorescein succinimidyl ester 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 annual report for current information on carcinogens.


carcinogen

a substance, organism, or agent capable of causing cancer

Project: QMS28

NOTE: A listing in the US Department of Health and Human Service’s Report on Carcinogens (ROC) identifies a substance or exposure circumstance as known or reasonably anticipated to be a human carcinogen and thus indicates a potential hazard


cardiopulmonary bypass

a procedure during which a machine takes over the function of the heart and lungs in order to sustain organ perfusion with oxygenated blood during cardiac surgery

Project: POCT14


caregiver

a person that provides care to people who need some degree of ongoing assistance with everyday tasks on a regular or daily basis

Project: PRE05


carnitine

a seven-carbon molecule with three important functional groups: a quaternary ammonium functionality, a carboxylic group, and a secondary alcohol

Project: NBS04, NBS09

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

See specimen carrier

Project: AUTO02, AUTO12


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 (operator)

individual or organization engaged in the commercial transportation of goods

Project: M29


carrier frequency

the proportion of individuals in a population who have a single copy of a particular gene at a specific locus

Project: MM17

NOTE: For disease-related genes, carrier frequency describes the proportion of individuals in a population who carry a recessive variant that is pathogenic for a specific condition.


carrier protein

a protein to which a specific ligand or hapten is conjugated

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


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.


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 sample into another sample and thereby erroneously affecting test results

Project: H44, H56, I/LA33, MM01


carryover

unintended transfer of material in a test method from a patient sample or reagent into other samples, reagents, materials, or parts of the instrument, potentially causing a carryover effect (ie, a quantifiable difference in other test results)

Project: EP47

NOTE: Carryover can also manifest as cross-contamination; for example, reagent clinging to a reagent probe contaminates the next reagent or insufficient washing of a reaction cell affects subsequent sample measurements.


carryover

unintended transfer of a fraction or element of a sample or reagent from one testing event to a subsequent testing event(s), occurring as a systematic event

Project: EP10


carryover effect

a quantifiable change in the measurement result (or raw data, such as signal) caused by sample or reagent carryover

Project: EP10


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: POCT07, POCT04


cascade reporting

strategy of reporting antimicrobial susceptibility test results on an individual patient's isolate in which secondary (eg, broader spectrum, sometimes more costly) agents may only be reported if an organism is resistant to primary agents within a particular drug class

Project: M39


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 (ie, from among subjects whose outcome and exposure status are already known) or prospectively (ie, 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

Alternate Term: nonfasting glucose; randomly timed 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, eg, "creatine" in "creatine kinase," the conversion rate of an indicator substance as substrate of a combined reaction, eg, 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," eg, "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)

Alternate Term: catalytic concentration

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

Alternate Term: 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

Alternate Term: 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

Project: GP16, PRE05


catheter specimen

a urine specimen collected from a catheter placed into the bladder through the urethra


catheter tubing

(urinary) a hollow long structure that permits the passage of urine from the urinary catheter to the drainage bag

Project: PRE05

NOTE: The tubing is usually made of flexible transparent plastic.


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, MM07, 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

a single dark or light element within a matrix-based two-dimensional symbol

Project: AUTO14


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.


cell wall stain

stain that highlights the cell wall (eg, calcofluor white, Gomori methenamine silver)

Project: M54


cell-free DNA

DNA located in body fluids such as plasma that is the result of shedding of primarily nuclear DNA from lysed cells during the normal process of cellular death (apoptosis) and/or cellular necrosis

Project: MM13

NOTE 1: Typical cell-free DNA fragment size is less than 180 base pairs on average, with size characteristics consistent with enzymatic nucleosome-associated cleavage; NOTE 2: Cell-free DNA in oncology applications may also be referred to as circulating cell-free tumor DNA; NOTE 3: Cell-free fetal DNA is genetic material that is released by the placenta and circulates in a woman’s blood during pregnancy.


cellulose acetate electrophoresis

electrophoresis in which microporous cellulose acetate (strips or plates) is the support medium for the solutes and solvents


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 congenital hypothyroidism

congenital hypothyroidism caused by deficient secretion of thyroid-stimulating hormone by the pituitary gland, which may be due to a pituitary (ie, secondary congenital hypothyroidism) or hypothalamic (ie, tertiary congenital hypothyroidism) abnormality

Project: NBS10

Source: Newborn Screening Glossary

NOTE: Central congenital hypothyroidism does not include secretion of a nonfunctioning thyroid-stimulating hormone molecule, which clinically resembles primary congenital hypothyroidism.


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


centrifugation tube

a glass or plastic tube in which urine is centrifuged for the purpose of preparing sediment for microscopic evaluation

Project: GP16

NOTE: Supernatant may also be tested when formed elements interfere with some chemical assays.


cerebrospinal fluid

the fluid in the ventricles of the brain, between the arachnoid mater and the 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

document provided by the producer of a reference material stating the intended use, measured value, measurement uncertainty, commutability with clinical samples when applicable, and a statement that the released product meets all quality system requirements and quality control specifications

Project: EP30


Certificate of Analysis

document provided by the manufacturer stating that the released product meets all Quality System Regulation requirements and quality control specifications

Project: M50

NOTE: Certificates of Analysis apply to individual lots of the product (ie, lot-specific).


Certificate of Compliance

document provided by the manufacturer stating that the product meets all Quality System Regulation requirements and quality control specifications

Alternate Term: COC

Project: M50

NOTE: Certificates of Compliance apply to all lots of the product (ie, product-specific).


certificate revocation list

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

process by which a qualified third party provides attestation that a system, process, product, or person conforms to specified requirements

Project: QMS04, QMS21, QMS25

Source: Quality Glossary


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

process by which an external organization gives written assurance that a service or person conforms to specified requirements

Project: GP23, GP48, QMS17


certification authority

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 prothrombin time/international normalized ratio value by a manufacturer or reference center, using a manual method based on a World Health Organization accepted protocol determined against an appropriate thromboplastin international reference preparation (or manufacturer or standard reference reagent) that has been calibrated against the appropriate World Health Organization standard in a multicenter study (ie, a minimum of three laboratories for a primary standard and two laboratories for a secondary standard)

Project: H54, H47


certified reference material

reference material, accompanied by documentation issued by an authoritative organization and providing one or more specified property values with associated uncertainties and traceabilities, using valid procedures (modified from JCGM 200:2012)

Project: EP12, JCGM 200:2012, MM06, I/LA28, EP29, MM20, EP30, C40, C62, H48, MM17, EP32

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); 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.


certified reference material

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

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: Certified reference materials 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, eg, 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 certified reference materials; NOTE 4: All certified reference materials lie within the definition of “measurement standards” or “etalons” given in the “International Vocabulary of Basic and General Terms in Metrology”; NOTE 5: Some reference materials and certified reference materials 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.


certified reference material

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” is the name of a certified reference material, 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, a US government agency formerly known as the National Bureau of Standards.


certified reference material

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: ISO 17511


certified reference material

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)

Project: C64

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 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 on at least two occasions and completed DNA analysis of the cystic fibrosis transmembrane conductance regulator (CFTR) gene with fewer than two cystic fibrosis–causing CFTR variants, or a sweat chloride concentration < 30 mmol/L and two CFTR variants, in trans, of which no more than one is known to be a pathogenic (cystic fibrosis–causing) variant

Alternate Term: cystic fibrosis screen-positive, inconclusive diagnosis

Project: NBS05


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


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

Project: DL01


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, C63

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 documentation must be retained in the laboratory for a specified period of time after completion of testing and the reporting of results.


challenge

for quantitative tests, an assessment of the amount of substance or analyte present or measured in a sample


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: MM14, QMS24


chance

random error

Project: GP45


chancre

a sore or ulcer located at the initial point of entry of a pathogen

Project: M54


change control

a systematic, documented approach to evaluating, testing, approving, and implementing modifications to products, process, or systems to ensure that adverse affects are minimized and that resources are used efficiently

Source: Quality Glossary


change management

systematic approach for defining, planning, coordinating, testing, tracking, and communicating a new or revised process and for preparing personnel for the transition to the future state

Source: Quality Glossary


change order

written order to the contractor to change something that was previously shown in the approved drawings or specifications

Project: QMS04


channel

smallest division on the intensity scale of a flow cytometer

Project: H62

NOTE 1: The smallest unit of measurement for fluorescence intensity is referred to as the channel number. In older analog instruments, data were acquired in 256 or 1024 channels. More recently, cytometers divide the intensity of light signals into 1024 or more channels; NOTE 2: Signals with high channel numbers are brighter than signals with low channel numbers. However, the quantitative relationship between signals defined by one channel number and those defined by another depends on the amplifier and photodetector voltage characteristics of a given protocol; NOTE 3: Assignment of intensity to channel can be linear or logarithmic; NOTE 4: Sometimes used as a shortened form of “spectral channel,” which refers to the portion of the light spectrum captured by a detector based on the cytometer’s optical pathway (eg, “PE [phycoerythrin] channel”).


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; 2) a code element; 3) a member of a set of elements on which agreement has been reached and that is used for the organization, control, or representation of information; 4) a letter, digit, or other symbol that is used as part of the organization, control, or representation of data; 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)

Project: AUTO01, AUTO07, AUTO02, AUTO03, AUTO12, AUTO14

NOTE 1: A character refers to an abstract idea rather than to a specific shape; 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; NOTE 3: A character is often in the form of a spatial arrangement of adjacent or connected strokes (ASTM F149).


characterization

(of a reference material) process of determining the property values of a reference material, as part of the certification process

Project: EP30

NOTE 1: The characterization process provides the values for the properties to be quantified; NOTE 2: In batch certifications, the characterization refers to the property values of the batch.


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


charge state

the total charge on an ion divided by the elementary charge (e)

Project: C64


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


chartable/unchartable comments

comments related in any way to a sample, patient, or set of results that are meaningful for the patient record (chartable), or meaningful only for laboratory staff (nonchartable)

Project: AUTO15


chartable/unchartable flags

alerts (or flags) from an analyzer that are meaningful for the patient record (chartable) or meaningful only for laboratory staff (nonchartable)

Project: AUTO15


charter

(v) the granting of authority or rights, stating that the grantor formally recognizes the prerogative of the recipient to exercise the rights specified

Project: QMS14

Source: Quality Glossary


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


check character

a value calculated from the encoded content in a linear bar code that is printed in a designated location in a bar code

Project: AUTO14

NOTE 1: This check character is typically not part of the human-readable text on the label; NOTE 2: The formula for the calculation is specific to the bar code symbology being used; NOTE 3: When a bar code is decoded by the bar code reader, the bar code reader performs the same symbology-specific calculation on the decoded content of the bar code and then compares the result of the calculation against the decoded check character. If the calculated and decoded values do not match, then a non-read error is generated. If the calculated and decoded values match, then the bar code reader accepts the encoded content as valid intended content and sends it to the attached computer application. The uncommon instance in which the calculated and decoded check characters match but the content of the bar code is incorrectly decoded is known as a substitution (misread) error


check sum character

a character defined by a specific mathematical algorithm to check the validity of the serial number that has been entered, either electronically or manually, into the newborn screening data system.

Project: NBS01


checklist

tool for organizing and ensuring that all important steps or actions in a process are considered or acted upon

Project: QMS15

Source: Quality Glossary


checksum

see check character

Project: AUTO14


chemical ionization

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, 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 chemical ionization source, this should be specified.


chemical ionization

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”)

Project: C50

NOTE: Chemical ionization spectra are simpler than electron ionization spectra and are often dominated by an intense protonated or adducted molecular ion (M+H) + with few or no fragment ions.


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


chemiluminescent immunoassay

an immunoassay 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


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

Project: M47

NOTE: 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


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.)

Alternate Term: chromatoidal body

Project: M28


chromoblastomycosis

a cutaneous or subcutaneous infection caused by darkly pigmented fungi (eg, Phialophora, Fonsecaea) characterized by the presence of dematiaceous 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

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, MM24


chylothorax

as a subtype of pleural fluid, indicates injury to the thoracic (lymphatic)duct with release of fat droplets/chylomicrons into the pleural space


chylous effusion

fluid resulting from chronic pleural effusion with breakdown of inflammatory cell membranes into cholesterol crystals

NOTE 1: This fluid can appear iridescent and is sometimes referred to as “pseudochylous”; NOTE 2: The term “chylothorax” indicates the accumulation of fat droplets or chylomicrons in the pleural space due to thoracic (lymphatic) duct disruption or obstruction.


ciphertext

data that has been transformed by encryption so that its semantic information content (ie, 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, ie, time of day, season of the year, and ingestion of meals

Alternate Term: chronobiological variation, diurnal variation

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


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

Alternate Term: 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

Project: DI02


classification

organization of varied items into mutually exclusive but related classes

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

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.


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


clinical cutoff

a cutoff that is derived from any correlation between the minimal inhibitory concentrations of an antimicrobial agent(s) for a pathogen(s) and the clinical outcome

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 decision support system

a health information technology system that is designed to provide physicians and other health care professionals with clinical decision-making tasks

Project: M39


Clinical Document Architecture

an HL7® v3 standard for the electronic representation of clinical documents

Project: AUTO16


clinical end point

an outcome that represents direct clinical benefit, such as survival, decreased pain, or the absence of disease

Project: H62

NOTE 1: Clinically meaningful end points that directly measure how a patient feels, functions, or survives; NOTE 2: End points that in themselves represent or characterize clinical outcome; objective outcomes include survival, disease exacerbation, and clinical event (eg, myocardial infarction or stroke); subjective outcomes include symptom score, and “health-related quality of life” (validated instrument); NOTE 3: Customarily, the basis for approval of new drugs.


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

Project: I/LA21

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

the highest minimal inhibitory concentration at which efficacy, based on clinical end point, a microbiological end point, or other accepted surrogate of clinical end point, would be predicted in patients based on clinical exposure-response relationships using efficacy in infected patients and associated human pharmacokinetics

Project: M23


clinical exposure-response relationship

the relationship of a favorable clinical response as a function of the drug concentration and minimal inhibitory concentration. It is expressed as the probability of a clinical response based on a clinically derived pharmacokinetic/pharmacodynamic predictor. Standard drug concentration–based exposure measures can be expressed as Cmax, area under the curve, Cmin, T>MIC, or other pharmacodynamic indices as defined by appropriate dose-fraction and exposure-response analyses and justified by the sponsor. Response refers to the direct measure of the pharmacologic effect of the drug and can be defined by a clinical end point, a microbiological end point, or other accepted surrogate of the clinical end point

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 or the detection of T-cell receptor excision circles 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

Alternate Term: pilot evaluation

Project: I/LA21

NOTE: Typically conducted by the sponsor, the evaluation may take place in a clinical setting or in the sponsor’s laboratory.


clinical information

information about the measurand that can be used to make a clinical or medical decision

Project: EP35

NOTE: In EP35, clinical information can be, for example, the expected range of concentrations, inherent biological variability, medical decision levels, and any other relevant information for each specimen type.


clinical information system

any health care information system responsible for housing clinical information

Project: POCT01

NOTE: Examples include laboratory information systems, clinical data repository, and electronic medical records.


clinical information system

any information system or computer system database responsible for housing clinical patient information

Alternate Term: CIS

Project: POCT02

NOTE: Examples include hospital information systems, laboratory information systems, clinical data repository, and electronic medical records.


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 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
Intermediate8–1615–19
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 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: I/LA21, 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

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

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, AUTO14


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, AUTO14


clinical laboratory reagent water

water that has been purified to achieve specifications related to resistivity (ie, ≥ 10 MΩ • cm referenced to 25°C), microbial content (ie, total heterotrophic plate count ≤ 10 colony-forming units/mL), organic impurities (ie, total organic carbon < 500 ng/g [parts per billion]), and particulate count (ie, ≥ 0.22 µm at, or near, the output stage using a purification system that includes a stage that blocks the passage of particles)

Project: C34


clinical performance

the capability of a binary examination to discriminate between subjects with and without a target condition

Project: EP12

EXAMPLE: Discrimination between women who are pregnant and those who are not pregnant; NOTE 1: Clinical performance is commonly measured with parameters such as clinical sensitivity and clinical specificity; NOTE 2: Clinical performance can be affected by bias, imprecision, and how the binary decision is made.


clinical performance

the sum of all attributes that might be important for clinical use of results from a test method when applied to a specific intended use

Project: EP19

NOTE: Performance specifications usually include clinical sensitivity and specificity, positive percent agreement and negative percent agreement, or other parameters of clinical usefulness.


clinical relevance

trait attributed to a genomic change or feature that is medically significant for diagnosis or management of a patient

Project: MM09


clinical reportable range

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 analytical measurement range

Project: C50, POCT09


clinical sensitivity

(for newborn screening) the proportion of newborns in the screened population who have the target disease and who have positive screening results

Alternate Term: diagnostic sensitivity

Project: NBS05, MM07, NBS09, NBS06, NBS07, NBS10

Source: Newborn Screening Glossary

EXAMPLE: In screening for cystic fibrosis, newborns with meconium ileus should be included in the calculation of sensitivity: Sensitivity = a / (a + c), in which a = a true-positive result and c = a false-negative result; NOTE 1: The clinical disease 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: Sensitivity = a / (a + c), for which a = true-positive screening test results and c = false-negative screening test results; see table in screening outcome; NOTE 4: “Clinical sensitivity” is not the same as “analytical sensitivity”; NOTE 5: 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; NOTE 6: In programs in which meconium ileus is excluded from the clinical sensitivity calculations, this deviation from the typical practice should be noted; NOTE 7: Clinical sensitivity refers to the assay’s ability to detect subjects with the condition or disease; NOTE 8: Clinical sensitivity is the fraction of clinically true positives divided by the sum of clinically true-positive plus clinically false-negative classifications; NOTE 9: As used in NBS06, clinical sensitivity refers to the ability of the newborn screening algorithm to identify subjects with severe combined immunodeficiency; NOTE 10: As used in NBS07, clinical sensitivity refers to the ability of the newborn screening algorithm to identify individuals with any form of Pompe disease; NOTE 11: See acylcarnitine.


clinical sensitivity

the ability of a test under study to give a positive result for subjects having the disease/state in question

Project: I/LA28

NOTE: See and use the definition of the preferred term diagnostic sensitivity.


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, I/LA21, H26, MM06, M53, MM05, MM20, C49

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: “Diagnostic sensitivity” is used outside of the United States and “clinical sensitivity” is used in the United States; NOTE 8: The term “clinical sensitivity” (United States) is equivalent to “diagnostic sensitivity” (Europe); NOTE 9: See seroconversion sensitivity.


clinical sensitivity

the ability of an examination to provide a positive result for subjects from the intended-use population who have the target condition (TC) for which they are being tested

Alternate Term: sensitivity

Project: EP12

NOTE 1: It is the proportion of subjects with the TC having a positive test result and is often expressed as a percentage; NOTE 2: Formerly, the term “diagnostic sensitivity” was used in CLSI documents.


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: MM19, MM22, MM21, MM26

NOTE 1: The term “clinical sensitivity” (United States) is equivalent to “diagnostic sensitivity” (Europe); NOTE 2: In Europe, the term “clinical” applies mostly to clinical studies of drugs, under much more stringent conditions.


clinical sensitivity

the ability of a test method under study to provide a positive result for subjects with the disease state or target condition in question

Project: EP19


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: C56


clinical specificity

(for newborn screening) the proportion of newborns in the screened population who do not have the target disease and who have negative screening results

Alternate Term: diagnostic specificity

Project: NBS09, NBS10

Source: Newborn Screening Glossary

NOTE 1: The clinical disease must be defined by criteria independent of the test under consideration; NOTE 2: The term “clinical specificity” (United States) is equivalent to “diagnostic specificity” (Europe); NOTE 3: Specificity = d / (b + d), for which d = true-negative screening test results and b = false-positive screening test results; see table in screening outcome; NOTE 4: “Clinical specificity” is not the same as “analytical specificity”; NOTE 5: See positive predictive value.


clinical specificity

the ability of a test under study to give a negative result for subjects not having the disease in question or the ability of the test to correctly identify the absence of the disease at a particular decision threshold (ie, a negative result and idenification of patients who do not have a disease) (Centers for Disease Control and Prevention. Diagnostic Sensitivity and Specificity Job Aid. Accessed 12 April 2023. https://www.cdc.gov/labtraining/docs/job_aids/additional_resources/Sensitivity_and_Specificity_Final_5_23_2022_508.pdf)

Alternate Term: diagnostic specificity (positive predictive value)

Project: I/LA28, MM19, MM20, MM26

NOTE 1: Also known as diagnostic specificity (positive predictive value); 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 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, I/LA21, 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 ability of an examination to provide a negative result for subjects from the intended-use population who do not have the target condition (TC) for which they are being tested

Alternate Term: specificity

Project: EP12

NOTE 1: It is the proportion of subjects without the TC who have a negative test result and is often expressed as a percentage; NOTE 2: Formerly, the term “diagnostic specificity” was used in CLSI documents.


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

Alternate Term: diagnostic specificity

Project: MM07, H62

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; NOTE 3: Also referred to as “diagnostic specificity” (proportion of truly nondiseased persons who are so identified by the screening test); NOTE 4: It is measured as the ratio of negative test results in individuals without the target condition and is often expressed as a percentage; NOTE 5: The condition or characteristic of interest must be defined by criteria independent of the test under consideration.


clinical specificity

the ability of a test method under study to provide a negative result for subjects without the disease state or target condition in question

Project: EP19


clinical specimen

See patient specimen

Alternate Term: patient specimen; diagnostic 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, C63

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 can 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

Alternate Term: diagnostic utility

Project: MM17, I/LA28, MM19, MM20, MM22, MM23, MM24, MM26

NOTE 1: Clinical utility can encompass prognosis and monitoring response to therapy, as well as diagnosis; NOTE 2: Also known as diagnostic utility.


clinical validation

the process by which a clinical expert accepts and interprets the results of an order or an order group

Project: AUTO16

NOTE 1: Interpretation of the results considers the results together with the biological history and the clinical and therapy information available for the patient; NOTE 2: This step may sometimes be performed by an expert system that uses knowledge rules and emulates the reasoning of the biomedical scientist, under its responsibility; NOTE 3: In HL7® Clinical Document Archictecture Release 2, this process is recorded as “authentication” of the laboratory report or of a subset of this report; NOTE 4: Also known as “medical validation.”


clinical validation

the process through which test results are shown to be 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 accuracy with which a test predicts the presence or absence of a clinical condition or predisposition

Project: MM17, MM19, MM20, MM23, I/LA28, MM26

NOTE 1: For genetic tests, the ability of a genotype to predict a phenotype associated with the clinical condition; NOTE 2: 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.


clinical validity

accuracy of detection of presence or absence of phenotype or disease

Project: H62


clinical validity

the strength of the relationship between a test and a clinical characteristic of interest

Project: MM09

NOTE 1: Typically expressed as clinical sensitivity and clinical specificity; NOTE 2: For genetic tests, the correlation between the genotype and a clinical phenotype.


clinically reportable interval

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


clinically reportable range

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

Project: H57

NOTE 1: For example, if it is desired to report a result that exceeds the analytical measurement range, 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; NOTE 2: The establishment of the clinically reportable range is a medical judgment made by the laboratory director, and is based in part on the assay technology.


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: I/LA33


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)


clone

a population of identical units, organisms, cells, or individuals that derive from the same ancestral line

Project: NRSCL8


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 manufacturer provides all hardware and software to the health care delivery organization

Project: AUTO11

NOTE: Many medical devices are closed systems.


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

Alternate Term: closed-tube sampling

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


cloud storage

a computing model in which data are stored on remote servers accessed from the Internet

Project: QMS26, QMS22


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

NOTE: A standard may, in addition, contain discretionary elements, which are clearly identified.


cluster of differentiation system

the identification of monoclonal antibodies with similar patterns of reactivity with human cells, which was the focus of numerous international workshops

Alternate Term: CD system

Project: H43, H42, H52

NOTE: Each group of antibodies was assigned a cluster of differentiation number. Not all antibodies in a cluster of differentiation 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 “cluster of differentiation antigen” (eg, CD4 antigen). An antibody that belongs to a given cluster is referred to as cluster of differentiation “x,” with the manufacturer’s nomenclature given in parentheses (eg, CD4 [Leu3a]).


Cmax

the maximum (or peak) serum concentration that a drug achieves after the drug has been administered and before the administration of a second dose

Project: M23


Cmax/minimal inhibitory concentration

the peak drug concentration divided by the minimal inhibitory concentration

Project: M23

NOTE: When the Cmax/minimal inhibitory concentration is reported, the point at which the calculation was determined (eg, after the first dose, day 1, or at steady-state) should be stated.


Cmin

the minimum blood plasma concentration reached by a drug before administration of a second dose

Project: M23


coagulation

the process by which the coagulation factors in blood interact to form a clot

Project: POL1/2


coagulation factor

one of a group of components of blood plasma that interact to form a blood clot

Project: H47, H48


coagulation factors

the various components of the blood coagulation system

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 (labile, antihemophilic factor, antihemophilic globulin, antihemophilic factor A, Factor VIII:C)
Factor IX (plasma thromboplastin component, Christmas factor, antihemophilic factor B)
Factor X (Stuart factor, Prower factor, Stuart-Prower factor)
Factor XI (plasma thromboplastin antecedent, antihemophilic factor C)
Factor XII (Hageman factor, surface factor, contact factor)
Factor XIII (fibrin stabilizing factor, fibrin stabilizing enzyme, fibrinase)
Other factors: (prekallikrein [Fletcher factor], high-molecular-weight kininogen [Fitzgerald factor])


coagulation meter

device to assess the clotting time

Project: POCT07


coagulation test system

a device used to measure the rate of blood or plasma clotting

Project: POCT14


coagulometer

an analytical instrument for measuring coagulation parameters

Alternate Term: coagulation analyzer

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


Code of Federal Regulations

Published by the Office of the Federal Register, National Archives and Records Administration as a special edition of the Federal Register


code set

any set of codes used for encoding data elements, such as tables of terms, medical concepts, medical diagnosis codes, or medical procedure codes

Project: AUTO16

NOTE: An example of an international code set is LOINC® (Logical Observation Identifiers Names and Codes).


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 medical laboratory measurement procedures, the calculated values for B (subscript 0 through 4) for the multiple linear regression equation

Project: EP10


coefficient of determination

the square of the correlation coefficient

Alternate Term: Determination coefficient

Project: NRSCL08


coefficient of variation

a measure of relative precision

Project: H62

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.


coefficient of variation

standard deviation divided by the mean (ISO 3534-1)

Project: EP10, C24, H57, H26, MM06, C51, QMS24, EP31, MM17, QMS23

NOTE 1: The ratio may be expressed as a percentage; NOTE 2: The term “relative standard deviation” is sometimes used as an alternative to “coefficient of variation” but this use is not recommended; NOTE 3: Coefficient of variation 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”; NOTE 5: It is calculated as 100 times the standard deviation, divided by the mean, and expressed as a percentage; NOTE 6: The coefficient of variation is commonly reported as a percentage; NOTE 7: The predecessor term “relative standard deviation” is deprecated by the term coefficient of variation; NOTE 8: For a non-negative characteristic, the ratio of the standard deviation to the average; NOTE 9: A measure of relative precision.


coefficient of variation

for a non-negative characteristic, standard deviation divided by the mean (modified from ISO 3534-1)

Project: EP33

NOTE: It is often multiplied by 100 and expressed as a percentage.


coenocytic

aseptate with no or rare cross-walls separating the cells

Project: M54

NOTE: Examples include Mucorales, Entomophthorales, and Pythium spp.


coenzyme

a small nonprotein substance required in an enzyme reaction

Project: NRSCL8

NOTE: Some coenzymes are also substrates.


cofactor

a nonsubstrate coenzyme

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; EXAMPLE 1: 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 2: 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


cold ischemia time

the time from removal of the specimen from the body, when it is at body temperature, to the time it is stabilized; this time represents the period when the devascularized tissue is at room temperature or lower (eg, refrigerated)

Project: MM13


cold temperature

a temperature maintained thermostatically between 2 and 8°C (36 to 46°F).

Project: M40


collection device

(for newborn screening) a medical device used to collect blood spots for routine newborn screening

Alternate Term: specimen collection device

Project: NBS01, NBS09, NBS05, NBS10

Source: Newborn Screening Glossary

NOTE 1: The collection device has two components: a section for recording demographic and other requested information and a blood collection (specified filter paper) section with preprinted circles to be filled with the newborn blood drops; NOTE 2: If a preprinted circle is not present, local requirements must define the quantity of blood considered acceptable; NOTE 3: Once the blood is collected, the collection device becomes the specimen (also referred to as “blood spot specimen” or “dried blood spot specimen”) and is no longer considered a collection device; NOTE 4: This specimen collection device is also commonly referred to as a “Guthrie card,” “filter paper,” or a “blood spot card”; NOTE 5: See dried blood spot.


collection vessel

any tube or container, preferably plastic, which serves to contain the body fluid specimen

Project: H56


collision-induced dissociation

dissociation of an ion after collisional excitation (IUPAC 2006)

Project: C43


collision-induced dissociation

a process wherein a (fast) projectile ion is dissociated as a result of interaction with a target neutral species

Alternate Term: collisionally activated dissociation; CAD

Project: C50

NOTE: This is brought about by conversion, during the collision, of part of the ion’s translational energy to internal energy.


colloid

small, solid particles that will not settle out of a solution

Project: GP40


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

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.


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

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

Project: ASTM08, VET04, VET03


colorimetry

the measurement and analysis of color by comparison with a standard

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 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 human papillomavirus test is positive in the following clinical situations: 1) postcolposcopy follow-up of women treated for cervical intraepithelial neoplasia 2,3; 2) postcolposcopy follow-up of women not found to have cervical intraepithelial neoplasia 2,3 or adenocarcinoma in situ at initial colposcopy and referred for the evaluation of repeat atypical squamous cells of undetermined significance, atypical squamous cells—cannot exclude high-grade squamous intraepithelial lesion, low-grade squamous intraepithelial lesion, and atypical glandular cells not otherwise specified; and 3) follow-up of women age 30 and over having a normal Pap and a positive high-risk human papillomavirus test on the initial screen, and either a positive high-risk human papillomavirus test and/or an abnormal Pap on the 12-month follow-up exam.


combination antimicrobial agent

consists of two agents in a single compound in which at least one agent has antimicrobial activity. For antimicrobial susceptibility testing, the two agents are tested together in a single tube or well, plate, or disk. If only one agent has antimicrobial activity, that agent is listed first. For example, if drug A is a β-lactam and drug B is a β-lactamase inhibitor without antimicrobial activity, the combination is presented as A/B. For minimal inhibitory concentration tests, the concentrations of the agents are tested at a defined ratio over a series of dilutions or with one agent held constant and the other serially diluted. For example:

• Defined ratio of 2:1 (µg/mL): 128/64, 64/32, 32/16, 16/8, 8/4, 4/2, 2/1, 1/0.5

• One agent constant at 4 (µg/mL): 128/4, 64/4, 32/4, 16/4, 8/4, 4/4, 2/4

Project: M23

NOTE: When minimal inhibitory concentration values from combination antimicrobial agents are reported, it is preferred that the concentration of the first agent in the combination is reported.


combination immunoassay

an immunoassay that detects both antigen and antibody

Project: M53


combined standard measurement uncertainty

standard measurement uncertainty that is obtained using the individual standard measurement uncertainties associated with the input quantities in a measurement model

Alternate Term: combined standard uncertainty

Project: C51, EP32

NOTE 1: The symbol for a combined standard measurement uncertainty of the quantity y is uy or u(y); NOTE 2: See combined standard uncertainty.


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)

Alternate Term: combined standard measurement uncertainty

Project: ISO IEC Guide 99, EP29, EP30

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); NOTE 2: The symbol for a combined standard measurement uncertainty of the quantity y is uy or u(y) (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 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 in vitro diagnostic device.


commercial manufacturer

an entity that intends to put a test method or any of its components into distribution beyond its operational location. It implies that the entity complies with all local or regional regulation necessary to legally place the materials on the market. These are often referred to as in vitro diagnostic devices

Project: EP19


committee

a group of people appointed or chosen to perform a function on behalf of a larger group

Project: QMS14

Source: Quality Glossary


committee charter

rights delegated to a committee including scope of activity and terms of reference

Project: QMS14


common access point

an access point that can service medical information bus, point-of-care, and hand-held personal digital assistant devices

Project: POCT01


common blood coagulation pathway

the end phase of the coagulation cascade, which involves the activation of factor X by tissue factor/VIIa complex and/or factor IXa, and the subsequent 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

NOTE: Also known as "random variation" or "process variation".


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.


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 18153)

Project: ISO 17511, ISO 18153, C64, EP39

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 material) property of a given 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 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); NOTE 3: For EP14, other specified materials are patient samples intended to be measured by an in vitro diagnostic medical device.


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.


commutability

(of a reference material) 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

Project: EP30


commutability

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: ISO IEC Guide 99, MM06, EP23, EP21, EP29, EP26, C62, C64, QMS24, EP34, EP32

NOTE 1: The reference material in question is usually a calibrator, and the other specified materials are usually routine samples (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 (JCGM 200:2012, ISO 17511); NOTE 3: The stability of commutable reference materials should be monitored regularly (JCGM 200:2012); NOTE 4: A commutability statement is restricted to the measurement procedures as specified in a particular comparison (ISO 17511); NOTE 5: In commutability assessment of a reference material, comparisons among all applicable measurement procedures is desirable; NOTE 6: Closeness of agreement of measurement results is defined in terms of fitness for purpose as appropriate for the intended use of the reference material.


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).


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, EP31

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).


commutable

the attribute of acceptable commutability in a reference material, calibrator, control, or other process sample matrix

Project: EP10


companion diagnostic device

an in vitro diagnostic 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 in vitro diagnostic 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 in vitro diagnostic 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

agreement between patient results obtained for an analyte (measurand) using different measurement procedures within a health care system

Project: H26, EP31

NOTE: The results are considered to be comparable if the differences do not exceed a critical value established based on defined acceptance criteria.


comparability

closeness of the agreement between the results of the coagulometer/reagent system under evaluation with an established method

Project: H57


comparative FTH measurement procedures

rely on use as calibrants of serum containing various total hormone concentrations, in which the corresponding free thyroid hormone 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

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


comparative measurement procedure

measurement procedure whose performance characteristics are considered suitable for clinical use and with which a candidate measurement procedure can be compared to evaluate the latter’s suitability for clinical use

Project: EP27


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

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

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 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 measurement procedure

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


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 method

measurement procedure method that a continuous glucose monitoring measurement is compared with

Project: POCT05

NOTE: This term is commonly known in the CGM industry as “reference method.” The term “reference method” is often used synonymously with a comparison method or a comparator.


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 red blood cells to demonstrate ABO and/or other clinically significant antibody incompatibility

Project: I/LA33


compensation matrix

the mathematical inverse of the spillover matrix. The values of the compensation matrix are used to correct the spectral overlap resulting in fluorescence spillover

Project: H62

NOTE: See spillover matrix, fluorescence compensation, and spectral overlap.


competence

demonstrated ability to apply knowledge and skills to achieve intended results

Project: QMS03, QMS13, QMS01

Source: Quality Glossary


competence

ability to apply knowledge and skills to achieve intended results (ISO 9000)

Alternate Term: competency

Project: HS02, POCT10, GP23, GP48


competence assessment

evaluation of a person’s ability to perform a test and to use a testing device

Project: POCT08, POCT15

NOTE: Competence assessment includes all aspects of testing, from specimen collection to results reporting, and it is usually performed with specimens or samples containing known amounts of the analytes for which the specimens or samples are being tested.


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

Source: Quality Glossary

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

Source: Quality Glossary


competency

following successful completion of a training program, the assessment of a person’s ability to perform blood glucose testing

Project: POCT13, POCT17


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 assessment

evaluation of a person’s ability to perform a test including all aspects of testing, from specimen collection to result reporting


competitive assay

an assay based on the competition of labeled and unlabeled analytes for a receptor

Project: DI01, I/LA23


complaint

any concern about the laboratory’s operation

Project: QMS21

Source: Quality Glossary

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

Project: DI01


complementary

the property of two strands of nucleic acid that can hybridize by specific-base pairing between the nucleotides

Project: MM01, MM09, MM10, MM12, MM22, MM24


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

successful fulfillment of a requirement

Project: QMS17


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 rule, such as a specification, standard, policy, regulation, or law

Project: QMS15, QMS01

Source: Quality Glossary

NOTE: For the purposes of QMS15, compliance means complying both with regulatory and accreditation requirements and with the laboratory’s approved policies, processes, and procedures.


component

part of a finished, packaged, and labelled in vitro diagnostic 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 a microbial identification system for positive and negative reactivity, using biologic quality control organisms, with each batch, lot number, and shipment of microbial identification system

Project: M50


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


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

Alternate Term: target condition, event of interest

Project: EP12

NOTE: For analyte-detection examinations, TC can be generalized as the subject having the analyte (eg, virus). 


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 Standards for Reporting of Diagnostic Accuracy Initiative)

Alternate Term: target condition

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

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: MM09, GP45, I/LA21, H57, MM17, EP35


confidence interval

calculated bounds that capture the true concentration or activity of the measurand in the sample with certain probability

Project: EP19


confidence level

value (1 − α) of the probability associated with a confidence interval or a statistical coverage interval (ISO-19973-1)

Project: MM17


confidence level

1) the probability that the interval estimate contains the population parameter when the null hypothesis is true; 2) the probability the null hypothesis won’t be rejected when it is true

Project: EP07

NOTE 1: The probability is usually denoted as a percentage: 100(1 − α)%; NOTE 2: See alpha error.


confidence limit

a number or pair of numbers that define a confidence interval

Project: NRSCL08, MM17


confidentiality

the entrustment of information form one party to another for that party's exclusive use not imparted to others

Source: Quality Glossary

NOTE: "Confidentiality" is not synonymous with "privacy" 


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 is generally used for forensic confirmatory testing.


confirmatory assay

a modification of the immunoglobulin E 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 immunoglobulin E 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 immunoglobulin E antibody in human serum, competitive inhibition may not be technically possible to achieve

Project: I/LA34


confirmatory test

(for newborn screening) a test to prove or disprove the presence of a specific disease, group of diseases, or phenotypic difference suspected based on screening test results

Alternate Term: diagnostic test

Project: NBS03, NBS08, NBS09, NBS05, NBS02, NBS10

Source: Newborn Screening Glossary

NOTE: For newborn screening and identity confirmation, confirmatory testing must be performed on a new specimen, rather than on any existing screening specimen.


confirmatory testing

a test that establishes the presence or absence of a measurand by another method that is 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 previous testing that indicated that the patient is at higher risk for a clinical condition.


confirmatory testing

a second test that establishes the presence or absence of a measurand by a method with higher analytical sensitivity or specificity (or both) than the initial test; a procedure that is based on a different physicochemical method than an original screening assay and used to confirm positive screening test results

Project: C63

NOTE 1: Confirmatory tests are typically quantitative; NOTE 2: A confirmatory test determines whether a specimen is ultimately reported as positive or negative. Gas chromatography–mass spectrometry or liquid chromatography–tandem mass spectrometry is generally used; NOTE 3: When the screening test is negative and a second more sensitive and specific technique is used, this subsequent test is considered a definitive method or targeted testing; NOTE 4: Related terms include confirmation test, definitive method, and targeted testing.


conflict of interest

situation that has the potential to undermine the impartiality of an individual because of the possibility of differences between the individual’s self-interest and professional interest or public interest

Project: QMS05

Source: Quality Glossary


conformance

fulfillment of a requirement

Alternate Term: conformity

Project: QMS01, QMS02

Source: Quality Glossary


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.


congenital hypothyroidism

thyroid hormone deficiency that is present at birth and that may be permanent or transient

Project: NBS10

NOTE: See primary congenital hypothyroidism, central congenital hypothyroidism, subclinical congenital hypothyroidism, and transient congenital hypothyroidism.


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

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/LA34, I/LA20

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 immunoglobulin E reagent. In some recent fluid-phase assays, the conjugate may be a biolabeled allergen reagent.


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; NOTE 2: Conjugates of antibody with fluorochromes, radioactive isotopes, or enzymes are often used in immunoassays.


connectivity

the ability to reliably transfer data between a point-of-care testing device and a computer system database

Project: POCT02


connectivity

the ability to reliably transfer test information between a point-of-care testing device and an information system

Project: POCT01


Connectivity Industry Consortium

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 Connectivity Industry Consortium 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 Connectivity Industry Consortium specification forms the basis for the CLSI POCT01 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

a conclusive sequence generated from an assembly or alignment of multiple individual sequences coding for the same gene region, where differences between the individual sequences at distinct positions are represented by ambiguity codes

Project: MM18

NOTE: The consensus sequence represents the diversity between a number of individual sequences of interest.


consensus sequence

the final sequence generated from a compilation of overlapping sequences after base calling is complete at all positions

Project: MM09

NOTE: The consensus sequence is believed to represent 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)

Alternate Term: maintenance of a measurement standard

Project: ISO IEC Guide 99

NOTE 1: Conservation commonly includes periodic verification of predefined metrological properties or calibration, storage under suitable conditions, and specified care in use (JCGM 200:2012); NOTE 2: 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, with very little diversity

Alternate Term: conserved sequence

Project: MM18

NOTE: A known set of conserved sequences can be 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

air supply and exhaust system where the airflow always stays the same

Project: QMS04


construction

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

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

Source: Quality Glossary

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, diatomaceous earth, silica) or soluble (eg, ellagic acid) substance that activates the “contact phase of coagulation,” involving Hageman factor (factor XII), prekallikrein (Fletcher factor), and high-molecular-weight 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

Project: H47

NOTE: These activators are normally negatively charged particulate substances but may be soluble compounds.


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

Project: H21


container

an object that holds a specimen from an individual patient

Project: AUTO02, AUTO12, AUTO14


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 drawn (ie, the isolates were not present in the patient’s blood when the blood was drawn 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 (29 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


context of use

complete and precise statement that describes appropriate use of the biomarker assay and how the validated assay is allowed to be used. The context of use statement is based on the endpoint to which the assay has been qualified or validated (ie, exploratory, secondary, or primary). During drug development and regulatory review, the context of use statement also describes important criteria regarding the circumstances under which the biomarker is qualified

Project: H62

NOTE: Context of use is central to biomarker qualification.


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, QMS06, EP23, MM20, QMS11, QMS01

Source: Quality Glossary

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 to provide added benefits to the customer and organization; NOTE 3: Includes the actions taken throughout an organization to increase the effectiveness and efficiency of activities and processes to provide added benefits to the customer and organization; NOTE 4: The process of establishing objectives and finding opportunities for improvement is a continual process through the use of audit findings and audit conclusions, analysis of data, management reviews, or other means and generally leads to corrective (or preventive) action.


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 glucose monitoring

(CGM) a glucose monitoring system with a sensor that measures glucose levels at regular and frequent intervals (eg, every 15 minutes or less) over the wear period

Project: POCT05


continuous glucose monitoring lag time

the interval required for a change in blood glucose concentration to cause a change in the measured glucose reading

Project: POCT05


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


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.


contrived sample

a sample created to mimic a native sample

Project: EP35

NOTE: Commonly contrived samples are created by dilution or comixing of native samples or by adding or spiking measurand to native samples or to a manufactured sample with a matrix similar to native samples.


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

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.


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

(ie, 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: H47, H44, NRSCL08, MM10, MM12, VET03, C34, I/LA34, QMS23

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; 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 standard deviations, 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


control

the administration of an antimicrobial agent to an individual animal with a subclinical infection to reduce the risk of the infection becoming clinically apparent, spreading to other tissues or organs, or being transmitted to other individual animals

Alternate Term: metaphylaxis

Project: VET03, VET01, VET09

NOTE 1: On a population basis, control is the use of antimicrobial agents to reduce the incidence of infectious disease in a group of animals in which some individual animals already have evidence of infectious disease or evidence of infection; NOTE 2: Therapeutic use of antimicrobial drugs includes treatment, control (also known as metaphylaxis), and prevention (also known as prophylaxis); NOTE 3: See breakpoint, treatment, and prevention//prophylaxis.


control

device, solution, lyophilized preparation, or panel of collected human or animal specimens or artificially derived materials intended for use in the quality control process

Alternate Term: control material; quality control material

Project: POCT14, MM22, MM01, H62

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; NOTE 3: Substance, material, or article used to verify the performance characteristics of an in vitro diagnostic medical device; NOTE 4: In medical laboratories it should be similar to and is analyzed along with patient specimens. If different, it should have a recognized, defined response to analytical measurements; NOTE 5: Control materials may or may not have known measurand concentrations (ie, assigned values) within specified limits (eg, target value, standard deviation).


control

method or substance with known values used to monitor the status of a measurand to maintain its performance within desired limits

Project: MM09, MM17


control

a device, material, solution, or lyophilized preparation intended for use in the quality control process

Alternate Term: control material

Project: NBS05, MM24, NBS10

NOTE 1: The expected reaction or concentration of analytes and/or 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

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 condition

recipient reagent tested under normal operating conditions without any steps taken to deliberately increase the carryover effect 

Project: EP47

NOTE: The recipient reagent is used to establish the expected response in the absence of significant carryover.


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

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

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

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, QMS06


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

Alternate Term: control

Project: POCT08, MM03, POCT04, POCT15

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: Alternate terms include “procedural control,” “internal control,” “external control,” “onboard control,” and “built-in control.”


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

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: 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 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 (two standard deviations, 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 as a result of observed shifts and trends.


control material

See control

Project: I/LA28


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)

Alternate Term: quality control

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 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

Alternate Term: 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 (ie, manually)

Alternate Term: manual blood culture system

Project: M47


conventional quantity value

quantity value attributed by agreement to a quantity for a given purpose (JCGM 200:2012)

Alternate Term: conventional value of a quantity; conventional value

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

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 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; EXAMPLESa) 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 value

See conventional quantity value

Alternate Term: conventional quantity value; conventional value of a quantity

Project: C51


conventional value of a quantity

See conventional quantity value

Alternate Term: conventional quantity value; conventional value

Project: C51


conversion

process of changing records from one medium to another or from one format to another while maintaining the record’s authenticity, integrity, reliability, and usability

Project: QMS26


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

any temperature between 8 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


copolymer

a polymer formed from two or more different monomers

Project: GP40


copy

(verb) to make a reproduction of an original

Project: QMS26


copy

(noun) an imitation or reproduction of an original; a duplicate; a file that has the same data as another file

Project: QMS26


copy number variant

an insertion or deletion that involves a DNA fragment of 1 kb or larger

Project: MM09


copy number variation

the number of copies of a particular gene or chromosomal segment present in the genome of an individual, usually indicating insertions or deletions that involve a DNA fragment of one kb or larger

Project: MM26

NOTE: In tumor studies, copy number variation needs to be distinguished from tumor-associated somatic amplifications and deletions.


core biopsy

a cylindrical section of tissue that has been removed for pathology analysis, often from a formalin-fixed, paraffin-embedded block

Project: MM23


correct detection rate

percentage of occasions when the reference blood glucose level reached the alert setting and the continuous glucose monitoring system initiated an alert within a prespecified time window before or after the blood glucose reached the alert setting

Project: POCT05


corrected report

a change in a previously issued examination report intended to correct an inaccuracy, including changes in examination results, patient identification, reference intervals, interpretation, or other content

Project: QMS26

Source: Quality Glossary


corrected report

change made to remove or correct an error; generally, a corrected report derives from clerical or reporting errors and not from diagnostic errors

Project: QMS12

EXAMPLE: Correcting a typographical error from 15 ng/mL to 45 ng/mL.


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 (ISO 9001)

Project: QMS06, QMS11, QMS13, QMS17, QMS19, QMS24, QMS01

Source: Quality Glossary

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: EP18, POCT09, POCT07, 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: ISO 3534-1, H26, POCT04

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

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

Alternate Term: determination coefficient

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

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).


corrosive

any substance that causes visible destruction of human tissue at the site of contact

Project: GP05

NOTE: The Environmental Protection Agency defines corrosivity as a substance that is highly acidic (pH ≤ 2.0) or highly alkaline (pH ≥ 12.5).


corrosive

a substance that can cause damage to human skin at the site of contact

Project: QMS04


corrosive

having the quality of corroding or eating away; erosive (RHUD1.7CD)


cost

expenses incurred in the provision of services or goods

Project: GP45, GP49

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 and rectifying the outcomes

Project: QMS20


cost of quality

overall concept that includes understanding quality cost types, applying them to the laboratory’s or organization’s budget, and communicating the resulting quality cost information to improve the use of resources

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

Project: POCT09

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.


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

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)

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 or contractual 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

the amount of sequencing data that is available per position in the sequenced genome territory

Alternate Term: read depth

Project: MM09

NOTE 1: “Coverage” is a collective term for a target region after alignment; NOTE 2: “Read depth” is an individual term at each nucleotide position.


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, C51, EP30, EP32

NOTE: A coverage factor is usually symbolized k (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 next-generation sequencing, the number of reads at which increased coverage is unlikely to improve sequencing data quality

Project: MM09

NOTE 1: Generally refers to a specifically defined level of coverage or the number of times a region is resequenced under stated assay conditions; NOTE 2: The coverage threshold is generally the minimum coverage needed to yield valid or reliable results.


covert incident

an event intrinsically unrecognizable as life threatening at inception

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.


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


critical concentration

for each drug, the critical concentration is the lowest concentration that inhibits 95% of wild-type strains of Mycobacterium tuberculosis complex that have not been exposed to the drug but that simultaneously does not inhibit strains of Mycobacterium tuberculosis complex considered resistant that are isolated from patients who are not responding to therapy

Project: M24

NOTE 1: The “critical concentrations” of antituberculous drugs were adopted by international convention (JCGM 200:2012); NOTE 2: In 2018, the World Health Organization defined the critical concentration as the lowest concentration of an antituberculous agent in vitro that will inhibit the growth of 99% of phenotypically wild-type strains of Mycobacterium tuberculosis complex (WHO technical report 2018).


critical congenital heart disease

a group of heart defects that cause serious, life-threatening symptoms and need intervention within the first days or first year of life

Project: NBS03


critical control point

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: I/LA33

NOTE: If the critical control point 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


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

Alternate Term: critical materials; critical tasks

Project: I/LA33


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

Project: AUTO13

NOTE: A critical point can influence the behavior of the system’s user or be a system-performed calculation, interpretation, or algorithm.


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

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.)


critical-risk results

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 health care providers without delay to ensure urgent clinical evaluation and medical intervention

Project: EP23, AUTO15


cross-contamination

physical or chemical movement or transfer of materials from one component of an examination procedure to another occurring as a random event

Project: EP47


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: If 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-Enterprise Document Sharing

provides a standards-based specification for managing the sharing of documents between any health care enterprise, ranging from a private physician office to a clinic to an acute care inpatient facility

Project: AUTO16

NOTE: This is managed through federated document repositories and a document registry to create a longitudinal record of information about a patient within a given clinical affinity domain. These are distinct entities with separate responsibilities.


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

as used in NBS07, the presence in patients with Pompe disease of a mutant acid α-glucosidase protein that cross-reacts with antibodies against normal acid α-glucosidase 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: LA01, DI01, ILA18, I/LA23, I/LA28, I/LA34, I/LA20

NOTE: Within the context of this document, cross-reactivity has two meanings. First, it refers to a human immunoglobulin E 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 immunoglobulin E detection reagents bind to other human immunoglobulin isotypes (immunoglobulin G, immunoglobulin A, immunoglobulin M, immunoglobulin D).


cross-reactivity

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, C63, H62

NOTE 1: See specificity and selectivity; NOTE 2: In immunology, a systematic error in an immunoassay resulting in immunogenic recognition of substance different from the intended measurand, producing an analytical interference.


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


cryoglobulin

a mixture of globulins that precipitates when cooled and dissolves when reheated to body temperature

Project: I/LA30


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

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 viruses) or tissues, in a controlled environment, for purposes of identification or other scientific study, or for commercial and/or medicinal use


culture

1) 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; 2) the product resulting from the intentional growth of microorganisms

Project: M47, M24


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

the set of shared attitudes, values, goals, and practices that characterizes an institution or organization

Project: QMS16


culture medium

a substance or preparation used for the cultivation and growth of microorganisms or tissue

Project: M24


culture medium

a substance or preparation used for the cultivation and growth of microorganisms

Project: M47


cumulative antimicrobial susceptibility test data report

the report generated by analysis of antimicrobial susceptibility test results from a defined period of time that reflects the percentage of isolates of a given species or organism group that is susceptible to each of the antimicrobial agents tested; includes antibiograms and other relevant analyses presented in tabular, graphic, or other types of formats

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: QMS16, QMS19, QMS21, QMS06, QMS01

Source: Quality Glossary

EXAMPLES: Consumer, client, end user, retailer, receiver of product or service from an internal process, beneficiary, and purchaser (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: A customer can be internal or external to the organization and can include patients and health care providers, eg, physicians, nurses, laboratory staff.


customer

all components of a health care organization where the in vitro diagnostic device is installed

Project: AUTO09


customer

organization or person that receives a product or service (modified from ISO 9000)

Project: POCT07

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, the patient would be considered a customer, and the doctor, point-of-care 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

for a binary examination, the internal continuous response threshold above which the result is reported as positive and below which the result is reported as negative

Project: EP12, MM07, EP12-IG

NOTE 1: Competitive examinations behave in the opposite way, with results at lower response values than the cutoff reported as positive; NOTE 2: The cutoff is set during examination development; clinical performance cannot be evaluated until after the cutoff has been set; NOTE 3: Some binary examinations may have an equivocal zone for which the result is indeterminate. See equivocal zone.


cutoff level

See decision level

Alternate Term: decision level; decision threshold; decision point

Project: EP24


cutoff value

the quantitative value of a measurand that is used to decide whether the result is considered above or below a clinical or analytical decision point (usually positive or negative)

Project: I/LA23, C63


cutoff value

minimal inhibitory concentration (MIC) value that separates bacterial populations based on a specific parameter

Project: VET02

NOTE: Three cutoff values, clinical cutoff (COCL), pharmacodynamic cutoff (COPD), and wild-type cutoff (COWT), are generally used for breakpoint and interpretive category decision-making.
  • COCL – the MIC cutoff value selected by clinical and/or microbiological outcome vs MIC from prospective clinical studies.
  • COPD – the MIC cutoff value derived using pharmacokinetic-pharmacodynamic indices; NOTE: COPD is established solely on the basis of the relationship between physiological free-drug exposures (eg, in blood, epithelial lining fluid, or possibly urine or milk) and the microbial susceptibility parameter (ie, MIC values).
  • COWT – the MIC cutoff value that separates wild-type from non-wild-type bacterial populations on the basis of MIC distributions; NOTE 1: COWT is based on the MIC data associated with the epidemiological database derived from geographically diverse diagnostic laboratory surveys, which could include isolates derived from animals that were part of a clinical field trial; NOTE 2: See epidemiological cutoff value (ECV), which shares the same definition as COWT, ie, defining the highest MIC or smallest zone diameter for the wild-type population of isolates; however, in VET02, because clinical breakpoints are being defined by three cutoff values, COWT is used rather than ECV.     


cutoff value

quantitative value of the measurand that is used as the decision point between a positive and a negative result

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 immunoglobulin E antibody (eg, negative and positive cut-points)

Project: I/LA34

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

Alternate Term: CNMetHb, hemiglobincyanide, HiCN (methemoglobin cyanide, cyanferrihemoglobin)

Project: H15


cyanobacterium-like body

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)

Alternate Term: coccidian-like body

Project: M28


cycle threshold

number of cycles needed for an amplicon to become detectable above background

Project: MM16, MM17

NOTE 1: The cycle threshold value of each real-time polymerase chain 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; NOTE 2: In an experiment in which all polymerase chain reactions have similar efficiency, the cycle threshold value will be the lowest for reactions in which the initial template copy number was highest.


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

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

Alternate Term: CF


cystic fibrosis

an inherited chronic disease primarily affecting the lungs and digestive systems; it is due to a defective cystic fibrosis transmembrane conductance regulator (CFTR) gene and its CFTR protein product

Project: NBS05

NOTE: Present in about 30 000 people in the United States and 70 000 worldwide.


cystic fibrosis carrier

as used in NBS05, a heterozygote with a variant 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 variant identified through immunoreactive trypsinogen/DNA screening and then a negative sweat chloride test

Project: NBS05

NOTE: Infants who are cystic fibrosis carriers appear to be free of any signs or symptoms of cystic fibrosis disease, although a small percentage are identified by newborn screening because of a tendency to have increased immunoreactive trypsinogen concentrations.


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


cystic fibrosis–causing mutation

a DNA sequence alteration causing cystic fibrosis, if in trans with another cystic fibrosis–causing mutation


cystic fibrosis-causing variant

a DNA sequence alteration causing cystic fibrosis, if in trans with another cystic fibrosis–causing variant

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

most often, use of the term cytomegalovirus is meant to indicate human cytomegalovirus, 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 cytomegaloviruses.


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

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

facts used as a basis for reasoning, discussion, or calculation

Project: QMS12, QMS26, QMS01

Source: Quality Glossary


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

(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

(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 immunofluorescent–antinuclear antibody titers, and it includes tests with an instrumental readout of quantification such as ELISA–antinuclear antibody, 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 availability

the ratio of the number of available glucose readings to the number of expected glucose readings, usually given as a percentage

Project: POCT05


data confidentiality

the property that information is not made available or disclosed to unauthorized individuals, entities, or processes (ie, to any unauthorized system entity) (RFC 2828; ISO/IEC 7498-1, 7498-2, 7498-4)

Project: AUTO09


Data Encryption Standard

a US government standard that specifies the Data Encryption Algorithm and states policy for using the algorithm to protect unclassified, sensitive data (See Advanced Encryption Standard) (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

typically, a manufacturer-specific network server or more general computer system that acts as an observation reviewer to provide collection of point-of-care data and storage of data, and communication of data, quality assurance/quality control, and other point-of-care instrument and data management functions

Alternate Term: DM

Project: POCT02

NOTE: In addition to these functions, data managers usually provide other applications or services tailored to specific devices or point-of-care user needs (such as management of operators, reagent lot numbers/expiration dates, and reports for regulatory compliance).


data manager

typically, a network server that provides the services of an observation reviewer (eg, point-of-care data storage and forwarding, quality assurance/quality control, and other point-of-care 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 point-of-care user needs (such as regulatory reporting and operator management applications); NOTE 2: Data manager systems are specific instances of observation reviewer services.


data manager interface

specifies the Transmission Control Protocol/Internet Protocol network interface and protocol between a data manager and one or more access points

Project: POCT01


Data Matrix

a type of two-dimensional bar code symbology, specifically Data Matrix ECC 200 (and not older, obsolete versions of Data Matrix), that is selected for use by CLSI AUTO14

Project: AUTO14

NOTE: Data Matrix bar codes may be in one of two formats: square and rectangular. See details in CLSI AUTO14 Chapters 5 and 6.


data privacy

assurance that the confidentiality of, and access to, certain information about an entity is protected

Project: AUTO11


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, reference, or calibration curve.


datum error

measurement error of a measuring instrument or measuring system at a specified measured quantity value (JCGM 200:2012)

Alternate Term: datum error

Project: ISO IEC Guide 99


datum measurement error

measurement error of a measuring instrument or measuring system at a specified measured quantity value (JCGM 200:2012)

Alternate Term: datum error

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

Project: H21

NOTE: This term is used in the collection of blood from indwelling vascular access devices.


dead volume

the retention volume of a container above which aspiration and dispense can be performed reliably

Project: I/LA33


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

Alternate Term: dead volume

Project: GP40


deadspace ratio

the ratio of physiologic deadspace (and instrument deadspace, if applicable) to tidal volume

Alternate Term: pulmonary deadspace ratio, Vd/Vt

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, eg, a probability of life expectancy or freedom from disability, often expressed as quality adjusted life years.


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

Alternate Term: decision point, cutoff level

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

Alternate Term: decision threshold; decision point; cutoff level

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

an amount of the measurand (eg, concentration, activity) that is used as a threshold for making a medical decision

Alternate Term: medical decision point

Project: EP07

NOTE: Often, decision points refer to reference limits, but other concentrations, such as from medical guidelines, are also used.


decision point

See decision level

Alternate Term: decision level; decision threshold; cutoff level

Project: EP24


decision point

(medical decision point) a concentration of the measurand that is used as a threshold for making a medical statement

Project: EP09

NOTE: Often, decision points will refer to reference limits, but other concentrations, such as from medical guidelines, are also used.


decision threshold

See decision level

Alternate Term: decision level; decision point; cutoff 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)

Alternate Term: infectious waste

Project: ISO 15190, M29, QMS28, QMS04, QMS23

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; NOTE 2: Sterilization and disinfection procedures are often used for decontamination of infectious waste; other procedures are available for chemical and radioactive material decontamination



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

Project: C50

NOTE: It is applied to the separation of multiple charged spectra and/or chromatograms into their individual components.


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 vein thrombosis

an intravenous thrombus in a deep vein, usually in the proximal legs or pelvis, but may also occur in an upper extremity

Alternate Term: deep venous thrombosis

Project: H59


deep venous thrombosis

See deep vein thrombosis


deep-seated lesion

situated in the thoracic or abdominal organ/cavity

Alternate Term: deep-seated mass

Project: GP20

NOTE: It is usually not palpable and is visualized radiologically.


deep-seated mass

See deep-seated lesion

Alternate Term: 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

analytical techniques that are designed to target specific drugs or drug metabolites

Project: C63

NOTE 1: When adequately validated and controlled, these methods have the potential to be used to firmly identify a measurand of interest. The techniques considered capable of being used in this manner are two-dimensional and generally use chromatographic separation and mass spectrometric detection; NOTE 2: Definitive testing is not equivalent to confirmatory testing, which is a second analytically distinct method using a second unique aliquot to confirm a positive screening test; NOTE 3: A related term is targeted testing.


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

Alternate Term: confirmation analysis

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 DNA and RNA integrity and stability

Project: MM13


deidentification

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 deidentified if either:

• An expert or 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

• The data do not include any of the following 18 identifiers (of the individual, their 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) for dates that are directly related to an individual, including birth date, admission date, discharge date, death date, and all ages over 89 and all elements of dates (including year) indicative of such age, except that such ages and elements may be aggregated into a single category of age 90 or older

– Telephone numbers

– Fax numbers

– E-mail addresses

– 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 (for patient care devices)

– URLs

– Internet protocol addresses

– Biometric identifiers (eg, fingerprints, 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 is 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 health care facility.


deionization

the removal of ions from a solution by ion exchange

Project: ASTM08


deionized water

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, MM24


deletion

the genetic process by which a segment of DNA is deleted or lost during replication

Project: NBS09, NBS05

NOTE: The number of deleted nucleotides may vary from a single base pair to an entire gene or several neighboring genes.


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


delimiter

a character or sequence of characters marking the beginning or end of a unit of data, eg, a control character, blank space, comma, or other character or symbol that indicates the beginning or end of a character string, word, or data item

Project: AUTO14


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 which differences between consecutive results exceed a specified delta check limit

Project: EP33


delta checks

comparison of two consecutive results from a patient, based on specified criteria, as a laboratory quality improvement effort

Project: AUTO15


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.


demultiplexing

the process of assigning next-generation sequencing reads to their samples of origin based on the sequence of their corresponding molecular bar codes

Project: MM09


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; 2) the conversion of double-stranded DNA or RNA to a single-stranded state with minimal secondary structure

Project: MM10, MM12, MM24

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.


denaturation

the conversion of double-stranded DNA or RNA to a single-stranded state with minimal secondary structure

Project: MM09, MM01

NOTE 1: Denaturation is performed by heating, increasing pH, or adding agents such as formamide or urea; NOTE 2: After they have been 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 sequences aligned by a multiple alignment tool

Project: MM18

NOTE: A dendrogram is often called a “phylogenetic tree.”


denial of service

the prevention of authorized access to a system resource or the delaying of system operations and functions (RFC 2828)

Project: AUTO09


deoxypyridinoline

pyridinium compound formed during collagen maturation by crosslinking lysine and hydroxylysin side chains from different collagen molecules

Alternate Term: lysylpyridinoline

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

a type of nucleic acid; a polynucleotide having a specific sequence of deoxyribonucleotide units principally serves as the carrier of genetic information

Alternate Term: DNA


deoxyribonucleic acid

(DNA) a type of nucleic acid; a polynucleotide having a specific sequence of deoxyribonucleotide units and serving as the carrier of genetic information

Project: MM02, MM13

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, guanine, cytosine, and thymine. Essentially, two forms of DNA can be distinguished: genomic DNA from the nucleus (nuclear DNA of the chromosomes) and mitochondrial DNA.


depletion analysis

a procedure used to estimate the quantity of immunoglobulin E 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 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 immunoglobulin E 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 immunoglobulin E for their immunoglobulin E content. Difference in the total immunoglobulin E levels between the sham- and ragweed-absorbed serum represents the amount of specific immunoglobulin E that was depleted or removed from the serum by the solid-phase allergen. The sham-adsorbed immunoglobulin E antibody levels should be equivalent to unabsorbed serum levels. Elution of the ragweed-solid phase adsorbed immunoglobulin E 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.


depletion analysis

a procedure used to estimate the quantity of immunoglobulin E antibody in the calibration process of a prospective reference serum by removal of specific immunoglobulin E and detection of changes in total immunoglobulin E levels

Project: I/LA34


depth of coverage

in next-generation sequencing, the number of times a 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 region.


depth of coverage

the number of unique reads of a given nucleotide in the reconstructed sequence

Alternate Term: coverage

Project: MM24


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


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 speedoutside 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, inthe 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

a part of the Feasibility and Design Phase in the Establishment Stage of the Test Life Phase Model. Design considerations should include whether a new test method could have performance characteristics that meet needs in a way that is lacking from an existing test method, and/or whether it would meet a f 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 is agreed on during the design portion of the Feasibility and Design Phase; NOTE 2: Relevant system specifications should be established during the Feasibility and Design Phase. During the Development Phase, the test method 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

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


design input requirements

the physical and performance requirements of a product that are used as a basis for product design

Project: EP25


designated comparison method

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 or principal assigned characteristics for an analyte or process

Project: NRSCL13, C44


desk audit

review of documents, usually performed at a desk using the audited organization’s documentation

Project: QMS15

NOTE: Method to review documents to prepare for an audit.


detectability

the ability of an analytical method to detect small quantities of the component (IFCC-1978-QC Terminology)


detectability

the ability to discover or determine the existence, presence, or fact of a hazard

Project: EP23


detection capability

an umbrella term for a set of performance attributes that may be used to characterize measurement accuracy in the low-end region of the measuring interval

Project: EP35, H62

NOTE 1: The term “sensitivity” and its variants “analytical sensitivity” and “functional sensitivity” are not used in EP35 or the main text of H62 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); NOTE 2: Signaling presence of a measurand in a sample; NOTE 3: See sensitivity, analytical.


detection capability

umbrella term for a set of performance attributes that can be used to characterize measurement accuracy in the low-end region of the measuring interval. These performance attributes are limit of blank, limit of detection, and limit of quantitation

Project: EP19


detection limit

measured quantity value, obtained by a given measurement procedure, for which the probability of falsely claiming the absence of a component in a material is β, given a probability α of falsely claiming its presence (JCGM 200:2012)

Alternate Term: limit of detection; lower limit of detection

Project: NBS07, NBS04, C52, NBS09, MM17, EP39

NOTE 1: The International Union of Pure and Applied Chemistry 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” and “minimum detectable concentration” (or dose or value); sometimes used to indicate “analytical sensitivity”; NOTE 5: In quantitative and qualitative molecular measurement procedures, the lowest concentration of analyte that can be consistently detected (typically, in ≥ 95% of samples tested under routine medical laboratory conditions).


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

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

Alternate Term: limit of detection

Project: I/LA34

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 standard deviations 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

proportion of affected individuals with positive test results

Project: I/LA25


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

archaic, a gene


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

See and use epitope or antigenic determinant

Alternate Term: Epitope, antigenic determinant


developer

the term “developer” is used in CLSI EP45 to include notonly commercial manufacturers of test methods but also laboratories thatdevelop their own (eg, based on published literature) or modifyregulatory-cleared and -approved commercial test methods forimplementation in their own facility

Project: EP19, EP45

NOTE: Also known as a laboratory-developed test.


development

phase in the Establishment Stage of the Test Life Phase Model. During development, a test method is transitioned from initial conception through lockdown using systematic, iterative 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: AUTO01, EP10, AUTO02, AUTO03, POCT07, POCT04

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; NOTE 2: Device is a term that represents a range of diagnostic instruments deployed in point-of-care testing. 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; 1) 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); 2) 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; 3) 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

specifies the interface or communication connection between a device and an access point

Alternate Term: DAP

Project: POCT02


device and access point interface

specifies the interface between a device and an access point or concentrator

Project: POCT01


device communication controller

specifies the interface (principally output) of a point-of-care device or its docking station to an access point

Project: POCT01

NOTE: This is an IEEE definition, equivalent to “point-of-care device interface.”


device end user

end user in the health care delivery organization familiar with the medical device and its operation

Project: AUTO11


device messaging layer

the device messaging layer 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 POCT01 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 method discriminate between diseased and nondiseased subjects or between two or more clinical states

Alternate Term: clinical accuracy

Project: EP24, POCT13, EP19

EXAMPLE: discrimination between rheumatoid arthritis and systemic lupus erythematosus.


diagnostic accuracy

the ability of a test system to obtain the correct result, including both sensitivity and specificity

Project: MM03, MM22


diagnostic accuracy

the extent of agreement between the information from the test under evaluation and the diagnostic accuracy criteria

Project: 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 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

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; 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.


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)

Project: I/LA23

NOTE 1: The clinical disorder (eg, hypoglycemia or hyperglycemia) 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 continuous glucose monitoring, diagnostic sensitivity refers to effectiveness of detection of hypoglycemia or hyperglycemia. Sensitivity = true positives/(true positives + false negatives).


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, MM14, H60, MM03, MM23

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: 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 C50, a more practical definition relates to the signal-to-noise ratio; NOTE 6: The term sensitivity is often used as a synonym for the lowest concentration of an analyte that can be distinguished from background; 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 samples that have identification or integrity issues, or to detect clinically important changes in patient conditions.


diagnostic sensitivity

1) as used in CLSI document I/LA02, the ability of a test to correctly identify samples in which antinuclear antibodies are present; 2) as used in CLSI document I/LA34, the ability of a test to correctly identify samples in which allergen-specific immunoglobulin E antibody is present; it correlates the presence of allergen-specific immunoglobulin E antibody in the serum of patients who are defined by clinical criteria and/or designated reference laboratory tests as truly allergic

Project: I/LA02, I/LA34

NOTE 1: Sensitivity for antinuclear antibodies is ideally determined by testing a panel of serum samples previously determined to be positive for antinuclear antibodies by an accepted reference method or consensus evaluation. This serum panel should reflect samples from a variety of disease states in which antinuclear antibodies are found; NOTE 2: Sensitivity for immunoglobulin E antibody is ideally determined by testing a panel of serum samples from subjects with a positive history of allergic disease and evidence of immunoglobulin E 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

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/LA34, the ability of a test to correctly identify samples in which allergen-specific immunoglobulin E antibody is present; it correlates the presence of allergen-specific immunoglobulin E antibody in the serum of patients who are defined by clinical criteria and/or designated reference laboratory tests as truly allergic

Alternate Term: clinical sensitivity

Project: I/LA34

NOTE: Sensitivity for immunoglobulin E antibody is ideally determined by testing a panel of serum samples from subjects with a positive history of allergic disease and evidence of immunoglobulin E 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

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 specificity

the ability of a measurement procedure to give a negative result for subjects who do not have the 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 samples that do not have identification or integrity issues, and correctly exclude samples from patients who do not have clinically important changes in their conditions.


diagnostic specificity

as used in CLSI document I/LA02, the ability of a test to correctly identify samples in which antinuclear antibodies are absent

Project: I/LA02

NOTE: Specificity for antinuclear antibodies is ideally determined by testing a panel of serum samples previously determined to be negative to antinuclear antibodies 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.


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 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: I/LA21, I/LA23, MM10, MM03, MM12, C50, MM17, I/LA28, MM19, H60, MM23

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; NOTE 6: For purposes of continuous glucose monitoring, diagnostic specificity refers to effectiveness of detection of the absence of hypoglycemia or hyperglycemia. Specificity = true negatives/(true negatives + false positives); NOTE 7: 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; NOTE 8: The term “clinical specificity” (United States) is equivalent to “diagnostic specificity” (Europe).


diagnostic specificity

as used in I/LA34, the ability of a test to correctly identify samples in which allergen-specific immunoglobulin E antibody is absent; it correlates the absence of allergen-specific immunoglobulin E antibody in the serum of patients who are defined by clinical criteria and/or designated reference laboratory tests as truly not allergic

Alternate Term: clinical specificity

Project: I/LA34

NOTE: Specificity for immunoglobulin E 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 immunoglobulin E 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

the ability of a measurement procedure under study to give a negative result for subjects not having the disease/target condition in question

Project: EP19, I/LA20

NOTE: Formerly, the term “clinical specificity” was used in CLSI documents.


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

Alternate Term: patient specimen; clinical specimen

Project: M29


diagnostic specimen

any human or animal material, including but not limited to excreta, blood and its components, and tissue and tissue fluids collected for the purposes of diagnosis but excluding live infected animals

Project: PRE04


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, MM24

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

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 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

Alternate Term: confirmatory testing; supplemental testing

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 (ie, 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

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

Alternate Term: confirmatory testing

Project: MM12


dial

fixed or moving part of a displaying device that carries the scale or scales

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

nucleotides lacking a 3'-hydroxyl (-OH) group on their deoxyribose sugar

Alternate Term: ddNTPs

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

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; NOTE 4: For presentation of data for validation purposes, the reference concentration should be comparative measurement procedure values.


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

Project: MM11, MM24

NOTE 1: The process for establishing such criteria is discussed in Section 9 of CLSI document MM11; NOTE 2: See also indistinguishable.


differentiation assay

an assay that distinguishes between HIV-1 and HIV-2 antibodies

Project: M53


difficult sample

a specimen or sample that is inherently unstable, of limited quantity, heterogenous, or possessing other characteristics that make it unsuitable for storage and testing over time

Project: EP25


diffuse reflection

the reflection of light from a surface such that an incident ray is reflected at many angles, rather than at just one angle

Project: AUTO14

NOTE 1: Light is reflected from an object in two different ways: specular (mirror-like) and diffuse; NOTE 2: The proportions between the two types are dependent on the surface properties of the object being illuminated. A matte white surface produces a reflection that is almost exclusively diffuse, resulting in very limited specular reflection. Inversely, an optical-grade mirror produces a reflection that is almost exclusively specular, resulting in very limited diffuse reflection. For practical purposes, diffuse reflection’s light distribution can be considered to be omnidirectional; NOTE 3: On typical label-stock, diffuse reflection will be present and is used for reading bar code symbols


DiGeorge syndrome

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 DiGeorge syndrome will have a deletion of 22q11.2; NOTE 2: Patients with DiGeorge syndrome may be described as having complete or partial DiGeorge syndrome based on the severity of the thymic defect. “Partial” DiGeorge syndrome comprises 99% of patients who have a normal or hypoplastic thymus. Approximately 1% of patients have “complete” DiGeorge syndrome; 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. Newborns with complete DiGeorge syndrome will likely be identified by the T-cell receptor excision circle assays used for severe combined immunodeficiency newborn screening. They will require immune reconstitution (eg, thymic transplantation); NOTE 3: Newborn screening programs have observed infants with partial DiGeorge syndrome with low T-cell receptor excision circle levels at birth which increase over time, eventually reaching the normal range.


digestion

chemical or enzymatic process used to cleave proteins into smaller fragments, typically peptides

Project: C64


digital measuring instrument digital indicating instrument

measuring instrument that provides a digitized output or display

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

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

the US government standard that specifies the Digital Signature Algorithm, 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.


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.


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, eg, whole blood, plasma, or sweat

Project: C29


direct antiglobulin test

a test in which antihuman globulin is used to determine whether red blood cells have been coated in vivo with immunoglobulin G, complement, or both

Project: I/LA33


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 and that is usually under the control and responsibility of the department manager

Project: QMS20

NOTE: Direct costs include costs such as labor, reagents, or supplies that vary with the rate of output but are uniform for each unit of production.


direct FTH measurement procedures

measurement procedures in which hormone is isolated from the protein-bound moiety prior to direct measurement of the amount sequestered (eg, by immunoassay)

Project: C45


direct INR determination

international normalized ratio determination from a prothrombin time/international normalized ratio calibration line determined using certified plasmas without employing an international sensitivity index and mean normal prothrombin time

Project: H54, H47


direct lighting

light that is directed downward toward the work surface

Project: QMS04


direct method

measurement method in which the value of a measurand is measured directly, in the specimen, without diluting the specimen with reagents and without the need for supplementary calculations based on a functional relationship between the measurand and other quantities actually measured

Project: EP34


direct methods

experimental verification methods that rely on sample data collected for the purpose of verification


Project: EP45


direct oral anticoagulant

group of oral agents composed of direct thrombin inhibitors and direct factor Xa inhibitors

Project: POCT14


direct oral anticoagulant

orally administered therapeutic agent that targets a specific factor (eg, factor Xa or factor IIa) to inhibit coagulation

Project: H21


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 to determine the proportion or percentage of resistant Mycobacterium tuberculosis complex in the patient’s bacterial population

Project: M24


direct thrombin inhibitor

a class of drugs (either oral or intravenous) that directly inhibit the enzyme thrombin (without the need for a cofactor)

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: AUTO07, AUTO02

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 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

Alternate Term: directions of the sample; transportation system; instrument or specimen processing and handling device interfaces

Project: AUTO02


director

the person designated as having primary responsibility for the point-of-care blood glucose testing service

Project: POCT12, POCT, POCT17


disaggregation

the process by which platelet aggregates become separated into single platelets, resulting in a reversible change in transmittance or impedance

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 medically significant degree with another result obtained from the same sample, with a result from another measurement procedure, or with a well-substantiated medical diagnosis

Alternate Term: anomalous result; spurious result

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 assay

a serological assay that distinguishes among HIV antigens or HIV-1 and HIV-2 antibodies or a molecular assay that distinguishes between HIV-1 and HIV-2 RNA

Project: M53


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)

Project: MM11, MM24

NOTE: Ideally, each unrelated isolate is detected as unique, but, in practice, some are indistinguishable.


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

agent capable of causing disinfection (ISO 15190)

Project: ISO 15190


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, QMS28, QMS23

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

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

Project: VET03


disk diffusion

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: M02

Source: Microbiology Glossary

NOTE: 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, recorded in millimeters, and interpreted according to CLSI standards.


displaying measuring instrument

indicating measuring instrument where the output signal is presented in visual form (JCGM 200:2012)

Project: ISO IEC Guide 99


disposal

the process of eliminating or deleting a record, beyond any possible reconstruction

Project: QMS26

NOTE: Also known as destruction.


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 (eg, tumor tissues vs peripheral blood mononuclear cells) require different methods to achieve complete disruption; NOTE 2: Incomplete disruption results in significantly reduced nucleic acid yields.


distal

remote; farther from any point of reference (Dorland's Illustrated Medical Dictionary. 33rd ed. Elsevier, Inc.; 2019)

Project: GP41, PRE02

EXAMPLE: The wrist is distal to the elbow.


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).


diversity

differences observed between individual gene section sequences derived from several species of a genus (interspecies diversity) and from isolates belonging to the same species (intraspecies diversity)

Project: MM18

NOTE: Also often referred to as “variability.”


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

a mechanical and electrical interface that supports the use of a point-of-care device, typically employing legacy mechanical interfaces, connectors, protocols, and power delivery methods

Project: POCT01


docking station

equipment designed to physically connect and interface a point-of-care testing device, including all of the wiring, cables, ports, connections, power supply, and communication formats and protocols

Project: POCT02


document

(verb) the action of creating a record

Project: I/LA33, QMS26

Source: Quality Glossary


document

(noun) information and the medium on which it is contained (ISO 9000)

Project: QMS06, GP26, QMS02, QMS16, QMS26, QMS21, QMS25, QMS01

Source: Quality Glossary

NOTE: Documents may be paper based or electronic.


document

(noun) any recorded item of a factual or informative nature, either paper or electronic; written or electronically generated information and work instructions

Project: I/LA33

NOTE: Examples of documents include quality manuals, procedures, or forms.


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 variant

Project: MM19


donor specimen

a urine specimen collected from a subject for the purpose of forensic testing

Alternate Term: drug donor specimen

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 (eg, glucose) in these body fluids at that time

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 bag

a container that collects urine passed through a urinary catheter, to which it is connected through the catheter tubing

Project: PRE05

NOTE 1: Also referred to as a urine ostomy bag; NOTE 2: Bags connected to a nephrostomy tube instead of a catheter are called nephrostomy bags.


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 (eg, kidney and urinary tract, liver and gall bladder, pancreas, intestine, stomach, esophagus); 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

a specimen collected for laboratory testing, using an approved medical device composed of 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: NBS03, NBS02, NBS01, NBS07, NBS04, NBS09, NBS08, NBS05, NBS10

Source: Newborn Screening Glossary

NOTE 1: Specimens collected using an approved medical device should yield a reproducible volume of blood per spot (typically 75 to 100 µL for a 12.5-mm circle, 35 to 50 µL for a 10-mm circle); NOTE 2: In newborn screening, the dried blood spot specimen is ideally collected directly from a heelstick using no anticoagulant agents, because anticoagulant agents, particularly heparin and EDTA, interfere with certain assays.


dried blood spot

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

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 dried blood spot is ideally collected directly from a heelstick using no anticoagulants. Anticoagulants, particularly heparin and EDTA, have been shown to interfere with certain assays.


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)


drill

See exercise

Alternate Term: exercise; game

Project: GP36


driver mutation

(to include variant and oncogene) changes in the DNA sequence of genes because of variants, or oncogenes that cause cells to become cancerous and grow and spread in the body

Project: MM26

NOTE: Detecting driver mutations in tumor specimens can inform treatment plans to stop cancer cells from growing, including using drugs that target a specific mutation


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: I/LA34


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

Alternate Term: dot plot, contour plot, cytogram, two-parameter histogram

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

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 white blood cells. 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.


Duchenne muscular dystrophy

a severe, progressive form of muscular dystrophy (progressive wasting of muscles) that appears in early childhood and affects leg muscles before arm muscles and the proximal limb muscles before the distal ones

Project: MM17

NOTE: It is inherited as an X-linked recessive trait and characterized by an absence or decrease in the amount of the protein dystrophin.


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 next-generation sequencing, independent reads that are identical in nature and are typically removed to avoid biasing determination of allele frequencies

Project: MM09

NOTE: In metagenomics, “duplicate reads” typically refers to identical or nearly identical sequences that, because of artifacts in the sequencing process, appear present in numbers greatly exceeding expectations based on chance and that can produce an overestimation of the 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, variants within may have no deleterious effects to its host organism). Thus, the duplicated gene accumulates variants 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

fraction of an operational cycle for which signals can be measured

Project: C64


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 the mass spectrometer is focused on and attracting ions of a particular mass

Project: C50


dwell time

the amount of time a mass analyzer monitors ions of a particular m/z

Project: NBS04


dye

colored organic compound that, when dissolved in a suitable solvent, can impart colour to a material

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

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

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.


dysHb

See dyshemoglobin

Project: POCT11


dyshemoglobin

a hemoglobin form that is not functionally capable of reversible physicochemical association with oxygen

Alternate Term: dysHb

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 15-µg erythromycin and 2-µg clindamycin disks spaced 15 to 26 mm apart for Staphylococcus spp. and 12 mm apart for Streptococcus pneumoniae and β-hemolytic Streptococcus spp. to detect the presence of inducible clindamycin resistance

Project: M02

Source: Microbiology Glossary


D-zone test

a disk diffusion test using clindamycin and erythromycin disks placed in close proximity to detect the presence of inducible lincosamide (clindamycin, lincomycin, pirlimycin) resistance in staphylococci and streptococci

Project: VET01


E0

the baseline effect when there is no drug present (eg, drug concentration is zero), based on pharmacokinetic/pharmacodynamic modeling

Project: M23


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.


EC50

the concentration of drug at which half (50%) of the Emax is achieved, based on pharmacokinetic/pharmacodynamic modeling

Project: M23


echogenic bowel

when the fetal bowel displays an echogenicity or brightness equal to or greater than that of surrounding fetal bone, typically the iliac wing, or when there are dilated fetal bowel loops, both of which are associated with an increased risk of cystic fibrosis

Alternate Term: dilated bowel

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.


EDTA-modified carbapenem inactivation method

assay used to differentiate metallo-β-lactamases from serine carbapenemases in Enterobacterales isolates that are positive for the modified carbapenem inactivation method

Project: M02, M07

Source: Microbiology Glossary


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: GP26, QMS06, QMS14, QMS12, QMS01

Source: Quality Glossary


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).

Project: QMS06


efficiency

relationship between the result achieved and the resources used (ISO 9000)

Project: QMS14, QMS12


efficiency

the degree to which a system or component performs its designated functions with minimum consumption of resources

Project: AUTO08


efficiency

(of immunoassays) the percentage (number fraction multiplied by 100) of results that are true results, whether positive or negative

Alternate Term: agreement

Project: ILA18, I/LA23, 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


effluent

outflow or discharge of liquid waste, as from a sewage system, factory, or nuclear plant

Project: GP17


electrodeionization

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 (ie, 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 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.


electronic algorithm testing

testing by electronic means that does not involve a physical sample, usually using a software program that simulates an actual instrument, producing realistic values and comprehensive flags and errors, that represent the instrument output in the scenario being tested.

Alternate Term: dry testing, simulation

Project: AUTO15


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

the interface protocols and message formats required to exchange data between information systems or computers

Alternate Term: EDI

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; 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 point-of-care results.


electronic data interchange

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 point-of-care results.


electronic health record

the systemized collection of electronically stored patient health information in a digital format that is maintained by a provider, hospital, and/or health care system over time

Project: M39, MM26

NOTE: Automated access to these health records enables sharing across different health care settings and has the potential to streamline the clinician’s workflow.


electronic medical record

a computerized patient medical history

Alternate Term: EMR

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.


electronic records management system

electronic system in which records are collected, organized, and categorized to facilitate their preservation, retrieval, use, and disposition

Project: QMS26


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 representation 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

Project: MM18, MM24

NOTE: The data are a series of colored peaks where each peak represents one of the four different DNA bases.


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

NOTE: Each kind of molecule travels through the medium at a different rate, depending on its electrical charge and size.


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, MM24


electrospray ionization

an ionization technique that enables mass spectrometric analysis of labile and/or polar compounds

Project: NBS04, NBS09

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

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).


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.


Emax

the maximum possible effect (of the drug), based on pharmacokinetic/pharmacodynamic modeling

Project: M23


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

Alternate Term: 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


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

an Internet IPsec protocol designed to provide a mix of security services—especially data confidentiality service—in the Internet Protocol (RFC 2828)

Project: AUTO09


encoded content

data that has been converted into a machine-readable format, such as a bar code symbology

Project: AUTO14


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

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 specimen (eg, 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

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


end-user laboratory

in the context of CLSI EP45, end-user laboratory refers to the laboratory that is verifying and implementing a reference interval that may have been established elsewhere

Project: EP45


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

Project: M29

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.


enhanced antibiogram

an antibiogram for which the data are extracted, stratified, and displayed to answer specific questions or to help guide empirical antimicrobial therapy in select patient populations

Project: M39

NOTE 1: Data are generally stratified by one or more variables including patient location, type of infection, specimen type, patient comorbidities (eg, cystic fibrosis, burn), patient age, and resistance phenotype (eg, methicillin [oxacillin]-resistant Staphylococcus aureus, carbapenem-resistant Enterobacterales); NOTE 2: Also known as customized antibiogram or specialty antibiogram.


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)

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) the process of increasing in content or abundance

Project: MM09

EXAMPLE: Increasing the abundance of one measurand within a complex mixture of nucleic acids or cellular components by selectively removing other nonmeasurand nucleic acids or cell components.


enrichment

(nucleic acid or cellular) the process of increasing in content or abundance, eg, to increase the abundance of one analyte within a complex mixture of nucleic acids or cellular components by the selective removal of nonanalyte nucleic acids or cell components

Project: MM13


enrichment

process undertaken to specifically increase the concentration of an analyte

Project: C64


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

Project: GP49


entity

that which can be individually described and considered. (ISO 3534-1/93-2.1)

Alternate Term: item

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, vibration, and altitude

Project: POCT07


environmental factors

variables that might affect the performance or efficacy of products (eg, temperature, airflow, humidity, light)

Project: EP25


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


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

any of various proteins… originating from living cells and capable of producing certain chemical changes in organic substances by catalytic action (RHUD1.7CD)


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.


enzyme conjugate

one of the reagents of an immunoassay that has an antigen, analyte, or antibody complexed to an enzyme by a covalent linkage

Project: I/LA18, I/LA28


enzyme immunoassay

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.


enzyme system

an enzyme (or enzymes) and the necessary substrates and cofactors for an enzyme reaction

Project: DI01


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) 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

See enzyme immunoassay


enzyme-linked immunospot

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 enzyme-linked immunospot 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 epidemiological cutoff value for each agent is the value obtained by considering the wild-type distribution, the modal minimal inhibitory concentration/minimal effective concentration for each distribution, and the inherent variability of the test. Usually, the epidemiological cutoff value 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 minimal inhibitory concentrations/minimal effective concentrations are higher than the epidemiological cutoff value (for disk testing, those with acquired resistance mechanisms would show a zone diameter smaller than the epidemiological cutoff value).


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) or zone diameter value that separates microbial populations into those with and without phenotypically detectable resistance (non-wild-type or wild-type, respectively). The ECV defines the highest MIC or smallest zone diameter for the wild-type population of isolates

Project: M02, M07

EXAMPLE:

Category

Example of Categories for an
ECV of 4 
µg/mL and 19 mm

MIC, µg/mL

Zone Diameter, mm

Wild-type

 4

 20

Non-wild-type

 8

 19


• wild-type – an interpretive category defined by an ECV that describes the microbial population with no phenotypically detectable mechanisms of resistance or reduced susceptibility for the antimicrobial agent being evaluated.

• non-wild-type – an interpretive category defined by an ECV that describes the microbial population with phenotypically detectable mechanisms of resistance and reduced susceptibility for the antimicrobial agent being evaluated. 


epidemiological cutoff value

the minimal inhibitory concentration (MIC)/minimal effective concentration  or zone diameter value that separates microbial populations into those with and without acquired and/or mutational resistance based on their phenotypes (non-wild-type or wild-type). The epidemiological cutoff value (ECV) defines the upper limit of susceptibility for the wild-type population of isolates

Project: M38

EXAMPLE:

Interpretive Category

ECVs

MIC, µg/mL

Zone Diameter, mm

Wild-type

4

20

Non-wild-type

8

19


wild-type – an ECV interpretive category defined by an ECV that describes isolates with no mechanisms of acquired resistance or reduced susceptibility for the antimicrobial agent being evaluated

non-wild-type – an ECV interpretive category defined by an ECV that describes isolates with presumed or known mechanisms of acquired resistance and reduced susceptibility for the antimicrobial agent being evaluated


epidemiological cutoff value

the minimal inhibitory concentration (MIC) or zone diameter value that separates microbial populations into those with and without acquired and/or mutational resistance based on their phenotypes (non-wild-type or wild-type), with the ECV defining the highest MIC or smallest zone diameter for the wild-type population of isolates

Project: VET02, VET09

NOTE 1: Epidemiological cutoff value is also sometimes referred to as “ECOFF”; NOTE 2: See interpretive category (for epidemiological cutoff values); NOTE 3: An ECV is a stand-alone value used for the purpose of epidemiology and surveillance and not for clinical application.


epidemiological cutoff value

also called wild-type cutoff value, separates bacterial populations on the basis of minimal inhibitory concentration distributions. Epidemiological cutoff values are normally established on the basis of the minimal inhibitory concentration distribution data (phenotype) created from testing isolates derived from geographically diverse laboratory surveys

Project: VET05, VET04

NOTE: Epidemiological cutoff values are species specific (unless otherwise stated) and protocol specific, but independent of the rearing conditions and pharmacokinetics of any antibiotic treatment.


epidemiological cutoff value

the minimal inhibitory concentration or zone diameter value that separates microbial populations into those with and without acquired and/or mutational resistance based on their phenotypes (non-wild-type or wild-type), with the epidemiological cutoff value defining the highest minimal inhibitory concentration or smallest zone diameter for the wild-type population of isolates

Project: VET01

NOTE 1: Epidemiological cutoff value is sometimes referred to as “ECOFF”; NOTE 2: See interpretive category (for epidemiological cutoff values); NOTE 3: A cutoff value is a stand-alone value used for the purpose of epidemiology and surveillance.


epidemiologically related isolates

isolates cultured from specimens (eg, patients, fomites, the environment) at a discrete time and place as part of an epidemiological investigation of an outbreak and that are presumed to be related based on the epidemiological data collected during the investigation

Project: MM24


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.


epithelial cell abnormalities

precancerous cellular changes in the cervix that include a spectrum of cellular abnormalities such as atypical squamous cells of undetermined significance, atypical squamous cells—cannot exclude high-grade squamous intraepithelial lesion, atypical glandular cells, low-grade squamous intraepithelial lesion, koilocytosis, human papillomavirus effect, and high-grade squamous intraepithelial lesion, adenocarcinoma in situ, 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

(antigenic determinant) that portion of an antigen against which the specific binding region of a monoclonal antibody reagent is directed

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

(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

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

Alternate Term: Antigenic determinant; determinant

Project: ILA18, DI01, I/LA23, H56, I/LA28, I/LA34

NOTE: In the context of immunoglobulin E assays, allergenic epitopes are regions on allergens that bind directly to the immunoglobulin E 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

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


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 assays, allergenic epitopes are regions on allergens that bind directly to the immunoglobulin E 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.


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, QMS01

Source: Quality Glossary

NOTE 1: For the purpose of QMS13, equipment includes general purpose devices; NOTE 2: For the purpose of QMS01, equipment includes general purpose devices, analytical systems, and computer system hardware and software.


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.


equivalence

the condition of being equal or equivalent in value, worth, function, mean, etc.

Project: EP35

NOTE: For the purpose of EP35, equivalence refers to establishing evidence that the clinical parameters or clinical usefulness of results between the primary specimen type and the candidate specimen type are comparable for a given measurement procedure.


equivalence

property of a set of measurement results for a specified measurand, such that the absolute value of the difference of a pair of measured values from two different measurement results is smaller than a chosen limit related to the intended clinical use of the measurement results

Project: EP32


equivalent reference fluorophores

unit of fluorescence intensity; the number of reference fluorophores in solution that produce the same fluorescence signal as a single dyed microsphere or bead. The equivalent reference fluorophores value assignment is provided by the National Institute of Standards and Technology and is traceable to National Institute of Standards and Technology SRM® 1934 (or the equivalent) standard reference material

Project: H62


equivocal result

a test result, within a specified range of the cutoff value, that 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.


equivocal zone

internal continuous response (ICR) interval around the cutoff within which the final result cannot be reported as either positive or negative, but is reported as “equivocal,” with or without including the actual result value 

Alternate Term: indeterminate zone

Project: EP12, EP12-IG

NOTE 1: In most cases, an equivocal result triggers follow-up steps for obtaining a binary result; NOTE 2: Many binary examinations include an internal control that can indicate when the ICR is unreliable or an output cannot be reported. An equivocal zone is different than an equivocal result; NOTE 3: Example studies in EP12 assume all binary results are available (ie, no missing or excluded results); NOTE 4: Also known as “gray zone” in the medical laboratory and as “guard band” in chemical metrology.


ergonomics

study of the efficiency of persons in their working environment (ISO 15190)

Project: ISO 15190, QMS04

NOTE: This term includes biomechanics, work physiology, anthropomorphism, and man-machine interfaces (ISO 15190).


ERR

an Health Level Seven 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 requirement. If the measurement error in a patient’s result exceeds the total error requirement, the result is erroneous; NOTE 2: May also be referred to as an incorrect result or an unacceptable result.


error

(random [of measurement]) component of measurement error that in replicate measurements varies in an unpredictable manner (JCGM 200:2012)

Alternate Term: random error of measurement; random measurement error

Project: ISO IEC Guide 99, EP06, C51, QMS24, EP19

NOTE 1: A reference quantity value for a random measurement error is the average that would ensue from an infinite number of replicate measurements of the same measurand (JCGM 200:2012); NOTE 2: Random measurement errors of a set of replicate measurements form a distribution that can be summarized by its expectation, which is generally assumed to be zero, and its variance (JCGM 200:2012); NOTE 3: Random measurement error equals measurement error minus systematic measurement error (JCGM 200:2012); NOTE 4: The standard deviation of the random measurement error is sometimes called “imprecision.”


error

(systematic [of measurement]) component of measurement error that in replicate measurements remains constant or varies in a predictable manner (JCGM 200:2012)

Alternate Term: systematic error of measurement; systematic measurement error

Project: ISO IEC Guide 99, C51, EP06, QMS24, C24, EP19

NOTE 1: A reference quantity value for a systematic measurement error is a true quantity value, or a measured quantity value of a measurement standard of negligible measurement uncertainty, or a conventional quantity value (JCGM 200:2012); NOTE 2: Systematic measurement error, and its causes, can be known or unknown. A correction can be applied to compensate for a known systematic measurement error (JCGM 200:2012); NOTE 3: Systematic measurement error equals measurement error minus random measurement error (JCGM 200:2012); NOTE 4: “Measurement bias” is an estimate of “systematic measurement error.” NOTE 5: For qualitative tests, an erroneous finding of the test method, eg, the presence of an analyte when the analyte is not present, and vice versa.


error

(measurement) measured quantity value minus a reference quantity value (JCGM 200:2012)

Alternate Term: error of measurement; measurement error

Project: EP10, JCGM 200:2012, POCT05, H26, GP34, EP06, C58, C51, C56, EP27, MM20, EP26, H60, C62, C57, MM23, POCT06, H48, EP21, C24, EP34, MM24

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 (modified from 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; 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; NOTE 8: A difference between a computed, estimated, or measured value and the accepted true, specified, or theoretically correct value.


error

(of measurement) result of a measurement minus a true value of the measurand (VIM93)

Alternate Term: measurement error; total analytical error

Project: I/LA25, H54, MM10, 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

(allowable) 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

Alternate Term: allowable error

Project: EP06

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


error

a deviation from truth, accuracy, or correctness; a mistake

Project: GP26, GP23, QMS11, QMS24

NOTE: Error in the proficiency testing process leads to an unacceptable result. Error in proficiency testing has many subtypes and classifications. Error might be classified as to when it occurred in the proficiency testing 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

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: In EP23™, the term “error” includes but is used in a much broader sense than the VIM term “error of measurement.”


error grid

a scatterplot for comparing measurements obtained from two measurement procedures, eg, a candidate measurement procedure (y-axis) and a comparative measurement procedure (x-axis)

Project: EP27

NOTE: The error grid plot includes zones indicating the potential harm associated with measurement errors.


error of measurement

See error

Alternate Term: error; measurement error

Project: C51


erythrocyte

a red blood cell; the hemoglobin-containing cell of the cells found in peripheral blood

Alternate Term: ERC, RBC

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)

Alternate Term: red cell indices, RBC indices


esoteric

(testing) the analysis of “rare” substances or molecules that are not performed in a routine medical laboratory

Project: MM20


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 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 minimal inhibitory concentration 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 essential agreement; N is the total number of microbial isolates tested (modified from ISO 20776-2); NOTE 2: The overall essential agreement is expressed as a percentage (modified from 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)


essential element

an element that (1) a species cannot achieve normal, healthy growth or complete its normal lifecycle without and (2) is part of a molecule of an essential constituent or metabolite

Project: C38

NOTE 1: A trace element that is consistently detectable in human tissues or fluids is not necessarily essential. Many trace elements are so ubiquitous in the environment (eg, aluminum, lead) that they are “normally” found in human tissues and fluids. As analytical detection limits are improved further, other rare elements could also be detected at ultratrace levels; NOTE 2: The criteria used to establish essentiality in other areas of life science, eg, plant growth can be adapted, with some qualification, to the animal kingdom; NOTE 3: The element must be specific and not replaceable by another, and it must exert its effect directly on growth or metabolism and not by some indirect effect, such as antagonism of another element present at toxic levels; NOTE 4: A number of trace elements have been clearly identified as essential for normal, healthy growth in humans. While there may be some elements that are not universally accepted because of the paucity of data supporting claims for essentiality, they may be considered borderline candidates.


establish

the determination of the performance characteristics of a new or modified measurement procedure

Project: EP25


establish

define, document (in writing or electronically), and implement

Project: GP26, QMS01

Source: Quality Glossary


establishment

stage of the Test Life Phases Model; the Establishment Stage includes the design, development, and validation phases performed by the developer resulting in a tangible product

Project: EP45


establishment

stage of the Test Life Phases Model; for the purposes of EP19, the Establishment Stage includes the Feasibility and Design, Development, and Validation Phases performed by the developer, resulting in a tangible product

Project: EP19


establishment study

in the context of CLSI EP45, a study done to establish a reference interval for a specific analyte following an accepted methodology. Some sources may refer to this study as a validation study

Project: EP45


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.


etched

describes a process whereby a resultant bar code is generated by an ablative or reductive process

Alternate Term: reductive bar code generation

Project: AUTO14

NOTE: An initially confluent dark contrast layer (of polymer, paint, ceramic, etc.) is removed (mechanically, optically, or photochemically), exposing a lighter color beneath. Typically, this process can be observed in marker technologies that generate bar-coded tissue cassettes, microscope slides, and a growing number of specialized, small form-factor molecular diagnostics containers. This process is fundamentally different from the more typical bar code image generation process, in which darker contrast material (eg, ink) is applied or otherwise generated, (eg, by heat) to an initially light background field.


ethylene diamine tetraacetic acid

(EDTA) one of a class of aminopolycarboxylic acids that act as sequestering (also referred to as “chelating”) agents

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.


etiologic agent

a viable microorganism or its own toxin that causes, or might cause, human infection

Project: GP05, QMS28


etiologic agent

the causative agent of a disease (e.g., the microorganism that causes a specific infectious disease)

Project: H05


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, I/LA28


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


evaluation

analysis of completed or ongoing activities that determine or support the accountability, effectiveness, and efficiency of an activity or program

Project: QMS05


evaluation

(study) a generic term for any investigation that measures the performance capabilities of an assay

Project: M52


evaluation of formed elements

an inclusive term encompassing the tabulation of white blood cells in a representative sample of human blood by a standard classification scheme (ie, differential or “diff”), notation of the presence or absence of certain red blood cell abnormalities, and notation of platelet 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

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)


event

a single unit of measurement detected and counted by flow cytometry, typically an individual cell or particle

Project: H62

NOTE: A flow cytometer associates all light signals that occur without a gap in time with a single event and stores the light intensities in association with that event in the data file. If cells (or other particles) are spaced appropriately in the core stream and do not coincide in the laser beam, an event is the same as a cell or particle. If cells coincide in the laser beam, an event may be two or more cells.


event

(proficiency testing) a single round of proficiency testing/external quality assessment testing, which may include more than one challenge (specimen or sample)

Project: MM14, QMS24


event

generic term used to encompass the terms “incident,” “error,” and “accident”


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 with the object of determining the value or characteristics of a property (ISO 15189)

Project: QMS02, GP26, PRE04, QMS06, QMS11, QMS13, EP12, GP33, POCT07, POCT10, PRE01, GP23, QMS25, EP23, QMS22, QMS01, EP35

Source: Quality Glossary

EXAMPLE: A test procedure or measurement procedure; 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 a value of a property are called quantitative examinations; those that determine the characteristics of a property are called qualitative examinations (ISO 15189); 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; NOTE 6: Laboratory examinations are also often called assays or tests (ISO 15189); NOTE 7: In EP35, examinations are also called measurement procedures; NOTE 8: In EP12, laboratory examinations that determine a value of a property are measurement procedures; those that determine the characteristics of a property are called qualitative examinations.


examination (binary)

an examination that produces a binary output    

Alternate Term: qualitative, binary examination

Project: EP12

NOTE 1: Binary examinations can have an internal continuous response that has quantifiable values. However, there is no requirement to characterize these values except in proximity to the cutoff used to provide the binary result; NOTE 2: In EP12, whenever the term “qualitative examination” is used without a modifier, it is assumed to mean qualitative, binary examination.


examination (nominal)

an examination that characterizes a sample into multiple possible unordered categories   

Project: EP12

EXAMPLE: Blood type.


examination (ordinal)

an examination that characterizes a sample into multiple possible ordered categories

Project: EP12

NOTE: Common examples produce outputs such as 0, +, ++, +++, and ++++. 


examination procedure

set of operations, described specifically, used in the performance of examinations according to a given method (ISO 15198)

Alternate Term: analytical phase

Project: ISO 15198, GP26

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 (ie, 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

Project: SDELMT84, DI01


exclusion of venous thromboembolism

a claim that can apply to any method, the results of which can reliably exclude venous thromboembolism

Project: H59

NOTE 1: Regarding a D-dimer reagent, studies must demonstrate that the negative predictive value, sensitivity, and coefficient of variation at the threshold have sufficient power to exclude venous thromboembolism when the test is applied to patients judged to have a low or intermediate probability of venous thromboembolism determined using a pretest probability 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 pretest probability 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 negative predictive values 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

Alternate Term: game; drill

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

Project: HS02

NOTE: Caused by external factors.


exogenous

developed or originating outside an organism; caused by external factors

Project: POCT10


exogenous interferent

substance originating outside the body (eg, 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 coding regions (ie, 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

a transcribed region of a gene that is present in the mature messenger RNA

Project: MM19, NBS05


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 genetic analysis

molecular method applied following the identification of a single variant allele to test for the presence of additional variants

Project: NBS05


expanded measurement uncertainty

See expanded uncertainty

Alternate Term: expanded uncertainty

Project: C51


expanded measurement uncertainty

product of a combined standard measurement uncertainty and a coverage factor

Project: EP32

NOTE 1: The factor depends on the type of probability distribution of the output quantity in a measurement model and the selected coverage probability; NOTE 2: The expanded uncertainty of a quantity y is symbolized Uy or U(y). (JCGM 2012)


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)

Alternate Term: expanded measurement uncertainty

Project: ISO IEC Guide 99, C51, EP30

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; NOTE 5: The expanded uncertainty of a quantity y is symbolized Uy or U(y).


expected range

the range of values for a measurand in a typical healthy population

Project: NBS03, NBS05, NBS02, NBS01, NBS07, NBS09, NBS10

Source: Newborn Screening Glossary

NOTE 1: The expected range is a population distribution, not an analytical parameter, that can 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 might vary, depending on the reference population and the statistical methods used; NOTE 2: The expected range for newborn screening results might vary by calendar and gestational age; NOTE 3: For purposes of newborn dried blood spot 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 4: As used in NBS07, the range of acid α-glucosidase activity values measured in dried blood spot specimens from newborns without Pompe disease, as opposed to laboratory test results that show acid α-glucosidase activity values below the predetermined cutoff (ie, a result outside of the expected range, or an out-of-range result); NOTE 5: 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 6: Expected ranges may be specified separately for subpopulations such as full-term newborns, preterm and low birth weight newborns, and older infants; NOTE 7: As used in NBS07, the laboratory test result of any satisfactory dried blood spot specimen that shows acid α-glucosidase 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); NOTE 8: As used in NBS09, the range of C26:0-lysophosphatidylcholine values measured in dried blood spot specimens from newborns without adrenoleukodystrophy disease, as opposed to laboratory test results that show C26:0-lysophosphatidylcholine values above the predetermined cutoff (ie, a result outside of the expected range, or an out-of-range result); NOTE 9: As used in NBS09, the laboratory test result of any satisfactory dried blood spot specimen that shows C26:0-lysophosphatidylcholine values at or above the predetermined cutoff is out of the expected range and requires follow-up; NOTE 10: Also called “reference range” and “normal range,” although the preferred terms are “biological reference interval” or “reference interval”; NOTE 11: See in-range and out-of-range.


expected range

as used in NBS06, the range of T-cell receptor excision circle 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 specimen that shows T-cell receptor excision circle 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 newborn screening specimen that shows T-cell receptor excision circle values below the predetermined cutoff would be outside the expected range, or out of range.


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

Alternate Term: expiry date

NOTE: Expiry dates are assigned to in vitro diagnostic 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)

Alternate Term: expiration date

Project: ISO 18113-1, ISO 18113-2, ISO 18113-3, EP25

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). NOTE 4: Also referred to as “expiration date.”


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

a dose of drug administered to the body as measured in plasma or other biological fluids

Project: M23

NOTE: Various measures of acute or integrated drug concentrations can be used, such as maximum and minimum concentration (Cmax, Cmin) and area under the curve.


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, MM24

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 and form mature RNA.


expression

(antigen) in H62, the intracellular or cell surface presence of a protein molecule

Project: H62


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: MM22


extended measuring interval

the interval within which measurand concentration values are measured with acceptable accuracy by diluting a specimen before taking a measurement within the analytical measuring interval

Project: EP34


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

Alternate Term: XML

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).


extension

the 5′ to 3′ synthesis of DNA, starting from an annealed primer to generate a complementary strand of DNA

Project: MM09


extensively drug-resistant tuberculosis

Mycobacterium tuberculosis strains that are resistant to rifampin, isoniazid, at least one fluoroquinolone, and at least one of three injectable antimycobacterial agents (ie, kanamycin, amikacin, and capreomycin)

Project: M48


external assessment

systematic process conducted by an organization external to the laboratory to collect and analyze data to determine compliance with specified requirements

Project: QMS17, QMS01

Source: Quality Glossary

NOTE 1: External assessment can 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” can 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 can also be referred to as the assessment organization.


external asset

(or external specimen) an asset or specimen that was previously accessioned into at least one referring (external, outside) laboratory’s information system before receiving it into the performing laboratory for testing

Project: AUTO14

NOTE 1: An external specimen or asset will have one external accession or case identification for each referring laboratory that has accessioned it; NOTE 2: The universal location identifier of the referring laboratory is always different from the universal location identified of the performing laboratory, but the accession or case identification generated by the referring laboratory can overlap with a current or future accession or case identification generated by the performing laboratory that belongs to a different specimen and patient. 


external control

in FISH, 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

control material that mimics patient specimens and monitors the testing process from specimen application to result interpretation

Project: MM19, MM22, MM24


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, H62

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 failure cost

cost occurring after delivery or shipment of a product or during or after provision of service to the customer

Project: QMS20


external laboratory

see referring laboratory

Project: AUTO14


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

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)

Alternate Term: EQA

Project: H43, ISO Guide 43-1, GP26, H42, H26, 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 external quality assessment 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

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

Alternate Term: proficiency testing

Project: EP31


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: H52

NOTE: 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.


external quality control

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

Alternate Term: external quality assurance; EQA; proficiency testing; PT

Project: C50

NOTE 1: A “blank” quality control sample is not acceptable as an external (“blind”) quality control material, although it is appropriate as an internal (“bench”) quality control material; NOTE 2: Standards are acceptable external (“blind”) quality control specimens provided the analyst does not know the expected result for the standard.


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

cardiopulmonary bypass that circulates the blood outside of the body

Alternate Term: extracorporeal membrane oxygenation

Project: NBS03

NOTE: This procedure requires exposure to red blood cells and should be considered a transfusion of blood products for the purposes of newborn screening.


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


extracted ion chromatogram

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

Project: C50

NOTE: This function simulates selected ion monitoring, but offers no enhancement of sensitivity.


extracted ion chromatogram

a plot of signal intensity of one or more m/z values as a function of time from a series of continually collected mass spectra

Project: C64


extraction

See nucleic acid extraction


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 which prevents their general circulation (ISO 15190)

Alternate Term: fume hood

Project: ISO 15190


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)

Alternate Term: fume hood


extralabel 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: VET01, VET06, VET09


extrapolate

to estimate (the value of a variable) outside the tabulated or observed range

Project: H54

NOTE: International normalized ratios above 4.5 would be extrapolated, while those between 1 and 4.5 would be interpolated.


extremely low birth weight

birth weight < 1000 g

Project: NBS03


extrinsic blood coagulation pathway

the activation of Factor X by Tissue Factor/VIIa complex


extrinsic coagulation pathway

the activation of the clotting cascade, which starts with the interaction of factor VII and tissue factor

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

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


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: M54


exudate

as a subtype of pleural fluid, due to inflammation and characterized by high protein and presence of cells


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


f

prefix indicating that the pharmacokinetic parameter values or pharmacokinetic/pharmacodynamic index values are based on unbound (free) fractions of the drug

Project: M23


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

Alternate Term: controller

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.


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


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 customer expectations

Project: EP18, POCT07, QMS20, GP47

NOTE 1: Failure includes the laboratory’s 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 occurs 

Project: EP18, POCT07, EP23, GP47


failure mode and effects analysis

analysis technique for system reliability, based on assumptions of possible failure states of each component of a device or system (IEC 60812)

Alternate Term: FMEA

Project: POCT02


failure modes and effects analysis

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, GP33

NOTE 1: Failure modes and effects analysis 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”; NOTE 3: Failure modes and effects analysis is considered a “bottom-up” analysis; NOTE 4: See CLSI document EP18 for further information.


failure modes and effects analysis

systematic review of a system or process that examines how failures can affect performance

NOTE 1: Failure modes and effects analysis 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 Reporting and Corrective Action System

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

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

See false-negative result

Alternate Term: false-negative result

Project: I/LA28


false negative

a negative test result for a disease or condition when the disease or condition is present

Project: M53, MM22, MM24


false negative

an observation for which no event alarm occurs, although there is a relevant symptomatic event

Project: MM19


false positive

a positive test result for a disease or condition when the disease or condition is not present

Project: M47, M53, MM19, MM22, MM24

NOTE: For blood cultures, 1) a culture that yields a microbial isolate(s) that is determined not to be the cause of bloodstream infection, or 2) a culture with objective evidence of microbial growth (ie, an instrument signal that indicates microbial growth) but for which subcultures and stains are negative.


false positive

See false-positive result

Alternate Term: false-positive result

Project: I/LA28


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 dried blood spot 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 (ie, probability that the disease or state of interest is present in the target population).


false-negative rate

rate of negative test results for a disease or condition when the disease or condition is present

Project: POCT07


false-negative ratio

the ratio of subjects who have the disease, but who have a negative test result, to all subjects who have the disease (false negatives + true positives); false-negative ratio = false negatives/(false negatives + true positives)

Project: GP10, MM12


false-negative result

a negative test result for a patient or specimen that is positive for the condition or constituent being investigated

Alternate Term: false negative

Project: MM09, MM12, MM17


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 patient or specimen who is positive for the condition or constituent in question

Alternate Term: false negative

Project: POL1/2, I/LA23, MM01, H20


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)

Project: EP33

NOTE: In the context of EP33, a false-negative result indicates that a delta check alert did not occur when there was a sample issue or patient condition change that should have been identified.


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

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

Alternate Term: false negative

Project: I/LA28


false-negative screening result

screen-negative result in an affected newborn

Project: NBS01, NBS09, NBS05, NBS03

Source: Newborn Screening Glossary

NOTE 1: A screen-negative result indicating that an individual is not at increased risk for the primary target disease when the individual is found later to be affected; NOTE 2: For quantitative tests such as immunoreactive trypsinogen, this refers to an “in-range” result in an affected child; NOTE 3: For qualitative tests such as DNA analysis, this may include failure to detect cystic fibrosis transmembrane conductance regulator gene variants; NOTE 4: As used in NBS09, a screen-negative result of a laboratory screening algorithm (based on the detected C26:0-lysophosphatidylcholine concentration below the cutoff) reported for a newborn later diagnosed with adrenoleukodystrophy; NOTE 5: See primary target disease.


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 dried blood spot 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 acid α-glucosidase 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

rate of positive test results for a disease or condition when the disease or condition is not present

Project: POCT07


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 (ie, probability that the disease or state of interest is present in the target population).


false-positive rate

proportion of unaffected individuals with positive test results

Project: I/LA25


false-positive ratio

the 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 (false positives + true negatives); false positives/(false positives + true negatives)

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

a positive test result for a patient or specimen that is negative for the condition or constituent being investigated

Alternate Term: false positive

Project: MM12, MM17, MM09


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)

Project: EP33

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

a positive test result for a patient or specimen that is negative for the condition or constituent in question

Alternate Term: false positive

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

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

Alternate Term: false positive

Project: I/LA28


false-positive result

a positive test result for a patient or specimen who is negative for the condition or constituent in question

Alternate Term: false positive

Project: MM01


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 screening result

screen-positive result in an unaffected newborn

Project: NBS09, NBS01, NBS05, NBS03

Source: Newborn Screening Glossary

NOTE 1: A screen-positive result indicating that an individual is at increased risk for a target disease when the individual is found later to be unaffected; NOTE 2: For quantitative tests such as immunoreactive trypsinogen, this refers to “out-of-range” results in an unaffected child; NOTE 3: For qualitative tests such as DNA analysis, this may include detection of cystic fibrosis transmembrane conductance regulator (CFTR) variants in a carrier or detection of CFTR variants that are not actually present; NOTE 4: As used in NBS09, a screen-positive result of a laboratory screening algorithm (based on the detected C26:0-lysophosphatidylcholine concentration above the cutoff) reported for a newborn who does not have adrenoleukodystrophy; NOTE 5: See primary target disease.


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

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: Fault tree analysis is considered a “top-down” analysis; NOTE 2: Fault tree analysis is more efficient than failure modes and effects analysis for analyzing combinations of failure events and human-use failures; NOTE 3: Fault tree analysis and failure modes and effects analysis 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

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

a part of the Feasibility and Design Phase in the Establishment Stage of the Test Life Phases Model. This phase includes consideration of a potential test method, by the developer, concerning various issues that are relevant to the advisability of developing a new test method

Project: EP19

NOTE: Issues could include the potential market for the test method, client expectations, and strategic plans for the institution.


feature

a defined segment of single-stranded nucleic acid immobilized on a solid substrate (ie, 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, MM24


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

Project: C50

NOTE: The increase in signal-to-noise ratio observed is proportional to the square root of the number of scans averaged.


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


finding

conclusion drawn by evaluating the collected audit evidence against the audit criteria (modified from ISO 9000, ISO 19011)

Project: QMS15


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

Project: MM17


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, a laboratory information system)

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; NOTE 2: Firewalls intercept attacks before the operating system can even acknowledge them; 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.


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: I/LA33


first isolate

refers to the initial microbial isolate of a given species (with antimicrobial susceptibility testing results reported) recovered from a single patient during the time period analyzed (eg, one year) for the antibiogram regardless of specimen source, specimen type, antimicrobial susceptibility profile, or other phenotypical characteristics (eg, biotype)

Project: M39

NOTE: If analysis of a subset of isolates is being performed (eg, isolates from blood cultures or methicillin [oxacillin]-resistant Staphylococcus aureus isolates), “first isolate” would refer to the first isolate in that particular subset (ie, the patient’s first blood isolate or methicillin [oxacillin]-resistant Staphylococcus aureus isolate, respectively).


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.


first-order 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-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


first-tier screen

(for newborn screening) a single assay, combination of assays, physiological measurement, or assessment performed on all newborns to screen for a disease, group of diseases, or phenotypic difference as the first step in the laboratory screening algorithm

Alternate Term: first-tier screening; first-tier testing

Project: NBS03, NBS08, NBS09, NBS10

Source: Newborn Screening Glossary

NOTE 1: Also called “primary screening test”; NOTE 2: See laboratory screening algorithm, screening test, second-tier screen, and third-tier screen.


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

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

Alternate Term: Fluorescein isothiocyanate

Project: I/LA24

NOTE: This is often used to describe any covalent fluorescein conjugate regardless of the actual conjugation chemistry used.


fit-for-purpose

an approach to analytical validation in which the method is validated as appropriate to the intended use of the data and associated regulatory requirement

Project: H62


fitness for purpose

a term used to indicate that a method or service fits the analyst’s defined purpose for that measurand

Project: EP32


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 ion-selective electrode 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

Alternate Term: emergency shower

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

Alternate Term: process map

Project: QMS18, QMS02, QMS01

Source: Quality Glossary


flow crossmatch

a test for compatibility between recipient and donor by testing recipient cells with donor cells

Alternate Term: flow cytometric crossmatch

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

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


flow cytometry standard

data file standard for the output files generated by cytometry instruments

Project: H62


fluorescein isothiocyanate

the most common fluorochrome used for cell immunophenotyping

Alternate Term: FITC

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

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: Fluorescein isothiocyanate 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

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 compensation

a mathematical or electronic correction applied to flow cytometric data to account for the overlapping fluorescence emission from one fluorophore into the wavelength region where a second is to be measured when both are present on the same cell; the desired result is that each corrected signal should reflect the emission of a single fluorophore

Project: H62

NOTE 1: Compensation is achieved by subtracting a fraction of one measured fluorescent signal from each of the other fluorescent signals; NOTE 2: The correction needed is determined by measuring the signal from appropriate single-stained controls in each detector; NOTE 3: The number of signals involved is equal to the number of fluorophores (N) used, and the number of compensation coefficients to be determined is represented by an N × N dimensional matrix. Values for the correlation coefficients are determined by inverting the spillover matrix generated by analyzing single-color controls; NOTE 4: See spillover matrix, compensation matrix, and spectral overlap.


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 (eg, 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

Project: MM05

NOTE: In the context of molecular diagnosis of hematological malignancies, FISH is used to detect chromosomal rearrangements of specific genes.


fluorescence intensity

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

Project: I/LA24


fluorescence intensity

a measurement of the active, or apparent, amount of fluorophore bound to a particle or cell

Project: H42, H43, H52, H62

NOTE 1: 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; NOTE 2: Expressed as mean fluorescence intensity (MFI), median fluorescence intensity (MdFI), or geometric mean fluorescence intensity. In situations for which either MFI or MdFI may apply, H62 uses MFI/MdFI. This term does not indicate a mathematical ratio.


fluorescence minus one

a staining tube that contains all but one of the antibodies/fluorophores in a multicolor panel; it is used to interpret flow cytometry data and to identify and gate cells in the context of data spread in a given panel

Project: H62

NOTE 1: For some applications, it is useful to omit more than one antibody/fluorophore; when this is done, the staining tube is often referred to as FMx (fluorescence minus x number of antibodies/fluorophores); NOTE 2: “Full (panel) minus one” recently replaced “fluorescence minus one” in the flow cytometry vernacular. The definition (and “FMO” abbreviation) is the same.


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

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, fluorescence resonance energy transfer 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 spillover

overlapping fluorescence emission from one fluorochrome into the wavelength region where a second is to be measured when both are present on the same cell

Project: H62

NOTE 1: A fluorophore’s spillover signal intensity in the secondary detector (spillover value) is proportional to its signal intensity in the primary detector; NOTE 2: The number of spillover signals (N) is equal to the number of fluorophores used, and mathematically inverting the N × N spillover matrix generates the compensation coefficients needed for each fluorophore at each detector; NOTE 3: See percent spillover and spillover matrix.


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

Alternate Term: fluophor

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, MM24


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-ligand conjugate

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 amplifications that use fluorescent dyes

Project: MM03

NOTE: It plots fluorescence or change in fluorescence as a function of polymerase chain reaction 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

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, MM24


fluorophore

a chemical moiety that fluoresces

Project: H62

NOTE 1: A chemical that after stimulation with one wavelength of light emits light of a different, usually longer, wavelength; NOTE 2: In flow cytometry, “fluorophore” is often used interchangeably with “fluorochrome” or with the short form, “fluor.”


FN

the number of false-negative results


follow-up

(for newborn screening) actions taken to ensure that a newborn whose specimen is unacceptable or whose screening result warrants additional action receives appropriate repeat screening, diagnostic testing, clinical evaluation, and/or intervention

Project: NBS05, NBS02, NBS09, NBS03, NBS10

Source: Newborn Screening Glossary

NOTE: See intervention.


follow-up algorithm

(for newborn screening) documented process used to ensure that newborn screening results are communicated to the newborn’s specimen submitter and/or health care provider and that additional screening and/or diagnostic testing and clinical evaluation is completed. For affected babies, this process also includes ensuring that treatment is initiated and outcomes are monitored

Project: NBS07, NBS06, NBS02, NBS10

Source: Newborn Screening Glossary

NOTE: See follow-up, short-term follow-up, and long-term follow-up.


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

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, C63


form

a paper or electronic document on which information, data, or results are recorded

Project: QMS06, GP26, QMS02, QMS26, QMS25, QMS01

Source: Quality Glossary

NOTE: When 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

measurement of light at a low radial angle relative to the incident light source

Alternate Term: FSC, FS, low angle light scatter

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.


forward group

tests red blood cells with reagent anti-A and anti-B to determine the red cell antigens present on the red cell

Project: I/LA33

NOTE 1: A positive reaction of hemagglutination indicates the presence of the corresponding antigen on red blood cells; 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


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


fraction

a part of the whole of anything


fractional carboxyhemoglobin

(FCOHb) the substance fraction of carboxyhemoglobin

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.


fractionation

process undertaken to divide a mixture into multiple components with common characteristics or properties

Project: C64


fragile site

a nonstaining gap in the chromatin of a metaphase chromosome, eg, the fragile site at Xq27 in the fragile X syndrome


fragment analysis

electrophoretic analysis of DNA that has been digested with one or more restriction endonucleases

Project: MM19


fragmentation

the dissociation of a precursor ion into two or more product ions

Project: C64


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 free T4 leads to more convenient figures.


free immunoglobulin E

human immunoglobulin E that circulates in blood in an unbound state, free of therapeutically administered humanized immunoglobulin G antihuman immunoglobulin E, soluble immunoglobulin E receptors, or other binding factors

Project: I/LA20

NOTE: Research assays for free immunoglobulin E that use the alpha chain of the high affinity fragment crystallizable-epsilon receptor receptor as the immunoglobulin E 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 or total T3 is required

Alternate Term: FTI tests

Project: C45

NOTE: This definition concerns two distinct categories of tests. First, those in which the total hormone measurement is combined either with a thyroid hormone binding ratio test (eg, T3-uptake) or a measurement of thyroxine binding globulin. This approach leads to indices that correlate with, but cannot be considered as unambiguous estimates of the true free thyroid hormone concentration. The second category comprises techniques like indirect equilibrium dialysis, ultrafiltration, symmetric dialysis, and gel equilibration that may yield valid estimates of the free thyroid hormone fraction so that, after multiplication with the total concentration, a valid approximation of the true free thyroid hormone concentration is obtained. It is recommended to reserve the term “free thyroid hormone index” 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 the frequencies or their relative frequencies

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


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


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, NBS09


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: I/LA33


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, QMS23

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

Alternate Term: active hemoglobin, effective hemoglobin


functional oxygen saturation

See oxygen saturation


functional resolution

the size of copy number variant 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 copy number variant 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 (ie, 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

Alternate Term: exercise; drill

Project: GP36


gamete donor

the donation of an egg or sperm for the intention of achieving a pregnancy

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

Project: DI01


gap analysis

a process to determine actions to take to move an entity from its current state to a desired future state

Project: QMS19, QMS01

Source: Quality Glossary

NOTE 1: Also called need-gap analysis, needs analysis, and needs assessment; NOTE 2: Gap analysis consists of 1) listing of characteristic factors (such as attributes, competencies, performance levels) of the present situation (“what is”), 2) listing factors needed to achieve future objectives (“what should be”), and then 3) highlighting existing gaps that need to be filled.


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.


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 forward angle light scatter vs side scatter), 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 side scatter), 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, 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, MM24


gene

a chromosomal segment that codes for a single polypeptide chain

Project: MM02


gene

a chromosomal segment that codes for a single polypeptide chain or a structural molecule

Project: MM18


gene array

solid supports on which a collection of gene-specific nucleic acids have been placed at defined locations, either by spotting or direct synthesis. In array analysis, a nucleic acid–containing sample is labeled and then allowed to hybridize with the gene-specific targets on the array

Project: MM24

NOTE: See also microarray.


gene dosage

measuring the quantity of a variety of measurands, 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

Project: MM17

NOTE: If extra copies of a gene are present, intensity is greater than 100% on a gel or film; if one copy of the gene is missing, the intensity is approximately 50%.


gene panel

a group of genes or variants that cause indistinguishable phenotypes and are concurrently sequenced using next-generation sequencing

Project: MM09

NOTE 1: The gene panel is sequenced or investigated as a group and generally associated with similar clinical conditions and/or used for similar clinical indications tested in a similar manner; NOTE 2: This definition of “gene panel” refers to a specific phenotype or condition.


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

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, NBS09


generator

a firm or institution that creates waste

Project: GP05


generic ISI

an international sensitivity index 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)

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


genetic variant

a DNA sequence that varies from a reference DNA sequence

Project: NBS05

NOTE 1: In NBS05, “genetic variant” refers to a DNA sequence that varies from a reference DNA sequence in the cystic fibrosis transmembrane conductance regulator (CFTR) region; NOTE 2: Also called “variant” or “CFTR variant.”


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

Project: MM13, MM18


genomic DNA

total DNA from an organism or a cell, which includes both the chromosomes within the nucleus and the DNA in mitochondria

Project: MM17, MM09


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, MM22, MM24


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, MM17

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)


genotyping

technology that detects small genetic differences and determines differences in genetic complement by comparing a DNA sequence with that of another sample or a reference sequence

Project: MM24


genus

rank in taxonomic lineage

Project: MM18

NOTE: Genus is one rank higher than species.


geometric mean

the mean of n positive numbers obtained by taking the nth root of the product of the numbers

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

Project: MM13, MM19

NOTE: A germline variant 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.


gestational age

time since conception, measured in weeks and days or in completed weeks only

Project: NBS10

Source: Newborn Screening Glossary

NOTE: The most precise estimate of gestational age is derived from in vitro fertilization information, followed by ultrasonographic metrics, followed by the time from the first day of the last menstrual period.


gestational age

time from the first day of the last menstrual period

Project: I/LA25

NOTE: This can be determined directly by asking a woman the date of her last menstrual period (ie, using her “dates”) or indirectly by using an ultrasound scan measurement (usually the crown-rump length or a biparietal diameter). Ultrasound measures that confirm the last menstrual period 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 completed weeks

Project: NBS03, NBS05


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

standard for digital mobile communications, with a capability for international roaming

Project: AUTO09

NOTE: Global System for Mobile Communications 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 US. Traditional Global System for Mobile Communications 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)

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

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: POCT13, POCT17

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.


glycolytic inhibitor

agent that inhibits the use of glucose by blood cells

Alternate Term: antiglycolytic agent

Project: GP39, GP34


glycoprotein Ib-IX

the major platelet membrane receptor for von Willebrand factor

Project: H51


goal

broad statement describing a desired future condition or achievement without describing specific parameters

Project: QMS06, QMS16, QMS03, QMS12, QMS01

Source: Quality Glossary

NOTE 1: An example is “improve laboratory service”; NOTE 2: “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

Project: GP10, I/LA23

NOTE: Its use is deprecated.


Good Clinical Laboratory Practices

a set of guidelines designed to facilitate uniform and consistent data generation and reporting. Good Clinical Laboratory Practices encompasses both quality assurance and quality control principles into its standards

Project: H62


good laboratory practice

a quality system concerned with the organizational process and the conditions under which nonclinical health and environmental safety studies are planned, performed, monitored, recorded, reported, and archived

Project: H62


good laboratory practice

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. Good laboratory practice 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

Alternate Term: graded event, graded challenge

Project: MM14


graded event

See graded survey

Alternate Term: graded survey, graded challenge

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

Alternate Term: graded event, graded challenge

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

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


Graves’ disease

hyperthyroidism caused by stimulating autoantibodies directed against the thyroid-stimulating hormone receptor of the thyroid gland

Project: NBS10

Source: Newborn Screening Glossary


gravimetry

the process of measuring the mass (weight) of a substance

Project: POL1/2


grind

to homogenize by friction (eg, with a sterile mortar and pestle or tissue grinder)

Project: M54


gross square footage

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

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 (ie, 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, MM24


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."


hacking

a method used to modify a computer program or electronic device in a skillful or clever way, with harmful intent

Project: QMS22

NOTE: Hacking may involve the use of software or other devices that allow unauthorized access to computer system information without any interaction with individuals.


Hamming distance

the number of bases that are different between two different sequences, which may be complementary

Project: MM09

NOTE: The minimum Hamming distance is the minimum number of bases that need to be different between the two sequences to prevent hybridization of complementary sequences.


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.


handling

preexamination and postexamination activities involving the specimen

Project: PRE04

NOTE: Proper mixing of the specimen collection tube at the time of collection, storing the specimen at an appropriate temperature, allowing sufficient time to clot (for serum specimens), and packaging for transport are forms of handling.


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


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 (ie, it is not immunogenic by itself)

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

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

Project: POCT02


hardware token

a small physical device that an authorized user of computer services is given to aid in authentication

Alternate Term: security token

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, EP18, ISO 18113-1, EP23, EP27

NOTE: In EP23 and EP27, damage to property or the environment is considered harmful only if that damage directly harms people.


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

in glycohemoglobin (GHB) testing, the process by which GHB test results among laboratories are made comparable to a common reference

Project: C44


harmonization

achievement of equivalent measured quantity values (within clinically meaningful limits) for human samples examined for a stated measurand among two or more in vitro diagnostic (IVD) medical devices by applying an international consensus protocol in their calibration hierarchies when fit for purpose higher-order reference materials or reference measurement procedures are not available

Project: EP32

NOTE 1: Harmonization is a calibration hierarchy model used to achieve metrologically traceable quantity values for human samples (ISO 17511); NOTE 2: Harmonization is a special case of non-SI traceable standardization in which the calibration of two or more IVD medical devices is traceable to an international harmonization protocol that defines the highest level of metrological traceability for the stated measurand with no traceability to SI; NOTE 3: Harmonized is the condition in which harmonization (equivalence among quantity values) is achieved among two or more IVD medical devices (ISO 21151)


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


harmonization reference material

reference material used as a calibrator for an international harmonization protocol (ISO 21151)

Project: EP32

NOTE: Specifications for these materials are included in the harmonization protocol (ISO 21151)


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


Hashimoto’s thyroiditis

an autoimmune disease that causes chronic inflammation and, frequently, consequential failure of the thyroid gland

Project: NBS10

NOTE: Also known as “Hashimoto’s disease.”


hazard

potential source of harm (ISO 15190)

Project: ISO 15190, M29, HS11, ISO 18113-1, ISO 18113-2, ISO 18113-3, ISO/IEC Guide 51:1999, ISO/DIS 14971, POCT02, EP18, EP23

NOTE 1: A hazard may harm either a health care provider or a health care recipient (ISO/IEC Guide 51); NOTE 2: Depending on the measurand and the nature and extent of the measurement error, an incorrect in vitro device 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 that requires special handling, processing, or disposal because it is toxic, infectious, carcinogenic, explosive, or reactive

Project: ISO 14971, QMS28

NOTE: Hazardous wastes, regulated medical wastes, and most forms of low-level radiactive waste are hazardous materials.


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

Alternate Term: HAZMAT

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 in vitro diagnostic 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, QMS28

NOTE 1: Includes waste that is flammable, combustible, ignitable, corrosive, toxic, reactive, injurious, or infectious (ISO 18113-1); NOTE 2: 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; NOTE 3: This includes chemical wastes that might be flammable, explosive, reactive, corrosive, toxic, carcinogenic, infectious, bioconcentrative, potentially lethal, irritating, or strongly sensitizing; 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

risk analysis method based on guidewords used for the proactive investigation of failure conditions within a system or device (IEC 61882)

Alternate Term: HAZOP

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 application

software application used for clinical patient care that contains patient information

Project: AUTO14

NOTE 1: Such software typically contains an application programming interface that allows an end user to interact with information in a local or remote database; NOTE 2: Health care applications include instrument software, testing device software, middleware, and laboratory information system software


health care delivery organization

an organization, or group of related organizations, involved with the delivery of health care services

Project: AUTO11

NOTE: A hospital is an example of a health care delivery organization, as are a group of physician practices acting in concert in an area.


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 care provider

individual authorized to deliver health care to a patient (ISO 17593)

Project: ISO 17593, GP33, POCT08, PRE05, PRE01, GP23, POCT15

NOTE 1: 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 (ISO 17593); NOTE 2: This is a global term used to describe a person obtaining the specimen or sample and can include physicians, nurses, laboratorians, respiratory therapists, care assistants, and phlebotomists.


health care provider

health care professional (eg, primary care provider, neonatologist, pediatrician, disease specialist) who provides health care for an individual

Project: NBS09, NBS02, NBS05, NBS10

NOTE: See primary health care provider and specialty care provider.


health care provider

health care professional, usually in the community, who provides basic health care for an individual

Project: NBS03


health information exchange

the electronic sharing of health-related information among organizations within a region, community, or hospital system according to nationally recognized standards


Health Level 7

the Health Level 7 organization (www.hl7.org), an American National Standards Institute–accredited standards development organization focused on messaging to support the exchange of clinical and administrative health care data

Project: POCT01

NOTE: The Health Level 7 standard specifies a transport-independent messaging framework and structure that enables disparate health care information systems to exchange data.


Health Level 7

an American National Standards Institute–accredited standards development organization focused on messages that support the exchange of clinical data (www.hl7.org)

Alternate Term: HL7

Project: POCT02

NOTE: The Health Level 7 standard specifies a message framework and structure that enables disparate health care information systems to exchange data.


Health Level Seven

the highest level (application) communications model for open systems interconnection

Project: AUTO01, AUTO07, AUTO02, AUTO03

NOTE: Level 7 supports security checks, participant identification, availability checks, exchange mechanism negotiations, and data exchange structuring.


Health Level Seven International

(HL7) an international standard for interfaces used in health care

Alternate Term: HL7 International

Project: AUTO14


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

an organization that coordinates activities of all standards developers in the healthcare informatics area of American National Standards Institute organizations

Project: AUTO01, AUTO07, AUTO02


Healthcare Information Technology Standards Panel

an organization that coordinates activities of all standards developers in the health care informatics area of American National Standards Institute 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 EDTA 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 life-threatening pregnancy complication considered a variant of preeclampsia with features including Hemolysis, Elevated Liver enzymes, and Low Platelets (HELLP)

Project: NBS03

NOTE: HELLP syndrome occurs in approximately 10% of pregnant women with preeclampsia or eclampsia.


helminth

may refer to a nematode (roundworm), cestode (tapeworm), or trematode (fluke)

Project: M28


hemadsorption

adherence of certain red blood cells to the surface of monolayered cells

Project: m41

NOTE: Hemadsorption is mediated by expression of viral hemagglutinin proteins on the surface of cells infected by certain viruses (eg, influenza) and can occur in the absence of cytopathic effect.


hemagglutination

1) the clumping of red blood cells; 2) agglutination reactions using erythrocytes. (Cf. DI1)


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 (eg, influenza)

Project: M41


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: POCT13, POCT17


hematocrit effect

the influence of hematocrit on the ability for the device to obtain an accurate result

Project: POCT07


hematoma

localized collection of extravasated 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. 33rd ed. Elsevier, Inc.; 2019)

Project: GP41, PRE02


hematopoietic cell transplantation

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: Hematopoietic cell transplantation is a recommended treatment for severe combined immunodeficiency and many other primary immunodeficiencies.


hematopoietic stem cells

stem cells that give rise to other blood cells through hematopoiesis, which occurs in the red bone marrow in the core of most bones

Project: NBS09


hemiglobin

hemoglobin in which the iron atoms have been oxidized to the ferric state and which has then been bonded with cyanide ions

Alternate Term: methemoglobin, ferrihemoglobin

Project: H15


hemiglobincyanide

hemoglobin in which the iron atoms have been oxidized to the ferric state and which has then been bonded with cyanide ions

Alternate Term: cyanmethemoglobin, cyanferrihemoglobin, methemoglobincyanide

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

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

Alternate Term: Hb; Hgb

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

Alternate Term: HbA1c

Project: C44


hemoglobin derivatives

a hemoglobin type characterized by the heme-iron portion of the molecule

Project: C25


hemoglobin oxygen saturation

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)

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


hemoglobinopathy

an inherited blood disorder characterized by the presence of a structural hemoglobin variant or a quantitative difference in globin chain production

Project: NBS08


hemoglobin-oxygen binding capacity

the maximum amount of oxygen that can be carried by the hemoglobin in a given quantity of blood

Alternate Term: BO2

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.


hemoglobins

all those hemoglobin derivatives normally present in circulating blood. They include deoxyhemoglobin, oxyhemoglobin, carboxyhemoglobin, and hemiglobin (methemoglobin). 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

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


heparin

(unfractionated) a mixture of complex glycosaminoglycans (mucopolysaccharides) of widely varying molecular weight (5000 to 50 000 Da) derived from animal tissues, used for prevention and treatment of venous and arterial thrombosis

Project: POCT14


heparin

a polysaccharide characterized by its anticoagulant properties

Project: NRSCL08, H47

NOTE: There are a variety of heparin “types,” which have different affects on the activated partial thromboplastin time and prothrombin time coagulation tests. Unfractionated heparin is a class of intravenous drugs that indirectly (through antithrombin) inhibit the enzymes thrombin and to some extent, factor Xa. The activated partial thromboplastin time is proportionately prolonged in the presence of unfractionated heparin. Low molecular weight heparin 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 activated partial thromboplastin time. Pentasaccharide is a heparin analog of five heparin subunits that inhibits factor Xa and only marginally affects the activated partial thromboplastin time.


heparinized

specimens anticoagulated with a heparin salt(s)

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

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. 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

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/LA34, I/LA20

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 immunoglobulin E standard (calibration) curve. The second portion of the assay involves the measurement of immunoglobulin E antibody to a defined allergen specificity (eg, Ambrosia artemisiifolia, common/short ragweed). Once the analyte (immunoglobulin E) is bound in both the calibration and antibody detection sections of the assay, the same conjugated, antihuman immunoglobulin E detection reagent is added to both. The response results (counts per minutebound, optical density, fluorescence signal units) generated in the immunoglobulin E anti-short ragweed portion of the assay are interpolated from the (heterologous) total serum immunoglobulin E calibration curve in international units per milliliter (IUA/mL) or mass units per milliliter (ng/mL) of immunoglobulin E, which are calibrated back to an immunoglobulin E 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

Project: DI01


heterophile antibodies

antibodies produced against poorly defined antigens that react with immunoglobulins from two or more species

Project: I/LA30


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

Alternate Term: heteroantibody


heteroresistance

presence of preexisting subpopulations of microbial cells exhibiting higher levels of resistance toward an antimicrobial agent while the majority of the cell population within the same culture is phenotypically susceptible to the same antimicrobial agent

Project: M02, M07


heteroresistance

presence of two or more mycobacterial populations of a strain with different drug susceptibilities

Project: M24

NOTE: Heteroresistance is expected when drug resistance is emerging during inadequate therapy.


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

Project: DI01


heterozygosity

the presence of two different genotypes (single nucleotide polymorphisms) at a locus

Project: MM21


heterozygous

having the two alleles at corresponding loci on homologous chromosomes different for one or more loci

Project: MM17, MM09, NBS09

NOTE: In NBS09, “heterozygous” is used rather than “carrier” to describe females who have one variant in the ABCD1 gene, because “carrier” usually denotes that the individual will not be affected by a disease, which is not true for women who are heterozygous for adrenoleukodystrophy.


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

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

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

Alternate Term: HPLC


Hill coefficient

in pharmacokinetic/pharmacodynamic modeling, refers to the slope of the dose or exposure-response curve. The larger the value, the steeper the slope

Project: M23


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

abbreviation for Hospital Information System

Project: AUTO02, AUTO03


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


HISB

abbreviation for Healthcare Informatics Standards Board

Project: AUTO02


histochemical stain

stain performed on a tissue specimen to aid in visualizing structures, including fungi

Project: M54


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

Alternate Term: 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 examination results from a sample that are declared positive

Project: EP12


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”

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

Project: DI01


homogeneity

the condition of being of uniform structure or composition with respect to one or more specified properties

Project: C37, EP30

NOTE: The converse of homogeneity is known as “heterogeneity.”


homogeneous

simultaneous amplification of the target and detection of the product in which data collection occurs throughout the process

Alternate Term: kinetic “real-time” assay

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 and amplicon detection performed in a single tube without an intervening separation or wash step

NOTE: Detection can be performed with specific reagents, such as molecular beacons. This is in contrast to heterogeneous polymerase chain reaction, in which the polymerase chain reaction amplicons are separated from amplification reagents before detection, usually by electrophoresis.


homogeneous, kinetic polymerase chain reaction

See real-time polymerase chain reaction

Alternate Term: real-time polymerase chain reaction

Project: MM03


homogenization

the process by which high-molecular-weight genomic DNA 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 before 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

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/LA34, I/LA20

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 immunoglobulin E antibody, for instance, the calibration curve is constructed with multiple dilutions of a serum containing a predefined amount of ragweed-specific immunoglobulin E antibody. Test sera are simultaneously analyzed using the same reagents for immunoglobulin E antiragweed. When complete, the response results (counts per minutebound, absorbance, fluorescence signal units) generated for the test sera are interpolated from the immunoglobulin E 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 immunoglobulin E antibody reference serum that has an assigned mass/volume quantity of allergen-specific immunoglobulin E antibody; NOTE 3: Homologous interpolation is the conventional calibration scheme used by most clinical immunoassays; however, it has been rarely applied to immunoglobulin E antibody assays, because large amounts of serum-containing immunoglobulin E 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 immunoglobulin E assays is impractical.


homozygous

having the two alleles at corresponding loci on homologous chromosomes identical for one or more loci

Project: MM17, MM19, MM09


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

a data management system that usually supports functions external to the laboratory, eg, admission, discharge, and transfer functions

Project: AUTO02, AUTO03


hospital 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

Alternate Term: health care information system

Project: I/LA33, 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 or a 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

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

the most common sexually transmitted virus and causative agent in the pathogenesis of cervical cancer and its precursor lesions in almost all cases

Alternate Term: HPV

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

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: NRSCL08, MM10, MM12, MM01, MM22, MM24

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”; 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 polymerase chain reaction amplification products

Project: I/LA28, MM09

NOTE: Hybridization can be performed with both nucleic acid target and probe in solution or with either bound to a solid support, such as a microtiter plate, glass, or membrane.


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.


hydrolysis probe

in real-time polymerase chain reaction, 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 polymerase chain reaction methods, the resulting fluorescence signal permits quantitative measurements of the accumulation of the product during the exponential stages of the polymerase chain reaction

Project: MM19


hyperacute rejection

a severe, nonreversible rejection of transplanted tissue that is mediated by preformed antibody response

Project: ILA29


hyperglycemia

high blood glucose levels or blood glucose higher than the target range for the patient

Project: POCT13

NOTE: Blood glucose 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

glucose level that is considered high as determined by the clinician

Project: POCT05

NOTE: The hyperglycemia threshold does not need to be the same as the alert threshold for hyperglycemia.


hyperglycemic event

an instance or instances in which the glucose level is at or above the hyperglycemia threshold

Project: POCT05

NOTE: Multiple glucose levels above the hyperglycemic threshold during this interval are considered a single hyperglycemic event.


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


Hypertext Transfer Protocol

a Transmission Control Protocol–based, application-layer, client-server, Internet protocol used to carry data requests and responses in the World Wide Web (RFC 2828)

Project: AUTO09


hyperthyroidism

excess of thyroid hormone, usually due to the overproduction of thyroid hormone by the thyroid gland

Project: NBS10

Source: Newborn Screening Glossary

NOTE: Also called “overactive thyroid.”


hyperthyrotropinemia

a biochemical pattern of elevated serum thyrotropin (ie, thyroid-stimulating hormone) levels accompanied by in-range thyroid hormone levels

Project: NBS10

Source: Newborn Screening Glossary


hypertrypsinogenemia

an elevated concentration of trypsinogen in blood specimens, as in the dried blood spot specimens obtained from newborns

Project: NBS05

NOTE: The meaning of “elevated health care professional (eg, primary care provider, neonatologist, pediatrician, disease specialist) who provides health care for an individual” 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: POCT13, POCT17


hypoglycemia threshold

glucose level that is considered low as determined by the clinician

Project: POCT05

NOTE: The hypoglycemia threshold does not need to be the same as the alert threshold for hypoglycemia.


hypoglycemic event

an instance or instances in which the glucose level is at or below the hypoglycemia threshold

Project: POCT05

NOTE: Multiple glucose levels below the hypoglycemic threshold during this interval are considered a single hypoglycemic event.


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

Project: NRSCL08


hypothyroidism

disease of the endocrine system in which the thyroid gland fails to produce sufficient thyroid hormone to meet the metabolic demands of the body

Project: NBS10

Source: Newborn Screening Glossary

NOTE 1: Also called “underactive thyroid”; NOTE 2: See primary congenital hypothyroidism, central congenital hypothyroidism, subclinical congenital hypothyroidism, and transient congenital hypothyroidism.


hypothyroxinemia

low total thyroxine levels commonly observed in preterm, low birth weight, or sick newborns in the absence of elevated thyroid-stimulating hormone and not due to central congenital hypothyroidism

Project: NBS10

Source: Newborn Screening Glossary


iatrogenic anemia

significant blood depletion as a result of volume removed for diagnostic blood sampling

Project: GP42, GP41, GP48, PRE02


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

Project: AUTO11

NOTE: Identification normally involves supplying a user identification, radio frequency identification badge, bar-coded badge without password, etc.


identifier

a single data element that is intended to indicate a person (patient), object derived from a person (patient), or the location of a person or specimen at the time of an event in health care

Project: AUTO14

NOTE: Many professional medical societies, international standards organizations, and governments require a minimum of a two-identifier match in order to uniquely identify a patient or specimen in health care


identity

the extent to which two sequences (nucleotide or amino acid) are invariant

Project: MM18


idiospecificity

a characteristic that describes the reactivity of an antiserum with a unique subset of a broad antigen class

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, AUTO07, AUTO02, AUTO03


IEEE 1073

a family of standards for medical device communications that are optimized for the acute care setting

Project: POCT01, POCT02

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 “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

Alternate Term: Illumination

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

Alternate Term: remedial action

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)

Alternate Term: primary container

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

Project: I/LA18


immunoassay

a ligand-binding assay that uses a specific antigen or antibody capable of binding to the analyte

Project: C45, NRSCL8


immunoassay

any laboratory method for detecting a substance by using an antibody reactive with it (RHUD2CD)

Project: I/LA34

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 immunoglobulin E and allergen-specific immunoglobulin E assays are noncompetitive heterogeneous immunometric assays.


immunoassay

a diagnostic test that uses a specific antibody or antigen to detect the presence of an analyte

Project: POCT15


immunoassay

any laboratory method for detecting an analyte using an antibody reactive with it

Project: I/LA28

NOTE: An immunoassay is a ligand-binding assay that uses a specific antigen or antibody capable of binding to the analyte.


immunoassay

any laboratory method for detecting a substance by using an antibody (pair) that is reactive with or binding to the measurand or substance of interest

Project: I/LA20, C63

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 and allergen-specific immunoglobulin E assays are noncompetitive heterogeneous immunometric assays.


immunoassay

an analytical procedure in which antibodies are used to detect or quantify the corresponding antigen

Alternate Term: immune assay

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

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

Alternate Term: immunohistochemical assay

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

Alternate Term: immunocytochemistry

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 immunoglobulin E 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, I/LA23, I/LA34


immunogenicity

the ability of a biomolecule to elicit an antibody response

Project: I/LA34


immunoglobulin

a glycoprotein composed of two heavy and two light chains that functions as an antibody

Project: I/LA34, NBS06, I/LA20

NOTE: Human immunoglobulins have been subdivided into different classes or isotypes (immunoglobulin M, immunoglobulin G1, immunoglobulin G2, immunoglobulin G3, immunoglobulin G4, immunoglobulin A1, immunoglobulin A2, immunoglobulin D, immunoglobulin E), 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

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

Project: DI01, MM05, I/LA28


immunoglobulin class

a classification of immunoglobins based on antigenic and structural differences of the heavy chain

Alternate Term: immunoglobulin isotype

Project: MM05, M36, NRSCL8

NOTE: There are five immunoglobulin classes: immunoglobulin G, immunoglobulin A, immunoglobulin M, immunoglobulin D, and immunoglobulin E.


immunoglobulin E

human immunoglobulin E 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/LA34, I/LA20

NOTE: It binds with high affinity to fragment crystallizable-epsilon receptor 1 mainly expressed on mast cells and basophils and fragment crystallizable-epsilon receptor 2 receptors on a number of other cells. Immunoglobulin E 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

Alternate Term: antigen-binding fragment

Project: NRSCL08

NOTE 1: Obtained by treating the molecule with the enzyme papain, specific fragments include: 1) 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; 2) 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; 3) 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; 4) 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; 5) 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; 6) 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.


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.


immunohematology

the study of antigen-antibody reactions as they relate to transfusion medicine

Project: I/LA33


immunohistochemical

of or relating to the application of histochemical and immunologic methods to chemical analysis of living cells and tissues

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

Alternate Term: immunohistochemistry

Project: H56


immunophenotyping

characterization of cells by the identification of cell-surface or intracellular antigens, using antibody reagents that recognize specific cell-associated molecules

Project: H42, H43, H52

NOTE: In H42, the cells that are immunophenotyped are lymphocytes and hematopoietic stem and progenitor cells; NOTE 2: In H52, the cells that are immunophenotyped are red blood cells and white blood cells.


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


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

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

Project: H58


implementation

the act of accomplishing some aim, executing some order, or carrying into effect

Project: I/LA33


implementation

putting into service, an instrument or method, by means of a definite plan or process

Project: H57


implementation

stage of the Test Life Phases Model; putting into service an instrument or test method by the end user for means of a definite plan or process

Project: EP19, EP45


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

extent to which replicate measures disagree with one another, regardless of their relationship to a reference value

Project: POCT05

NOTE: Imprecision is expressed numerically as standard deviation or coefficient of variation.


imprecision

the presence of random error, variability, or inconsistency

Project: POCT04


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: POCT14, H20, EP12, H26, EP23, EP27, EP09, EP26, EP05, C24, EP34, EP07, EP31

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; NOTE 4: See precision (of measurement); NOTE 5: For a qualitative, binary examination, imprecision can be characterized by the range of the interval from C5 to C95.


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

dispersion of independent results of measurements obtained under specified conditions

Project: EP10, EP14, I/LA23, C58, I/LA26, C48, H54, MM10, MM12, H57, C34, MM06, H59, GP34, MM19, MM01, C56, MM20, C40, MM22, H60, C62, C57, MM23, POCT13, POCT06, EP33, H48, C63

NOTE 1: For quantitative measurement procedures, it is expressed numerically as standard deviation or coefficient of variation; NOTE 2: It is expressed numerically as standard deviation or coefficient of variation; NOTE 3: It is expressed numerically as standard deviation or coefficient of analytical variation; NOTE 4: See precision.


imprecision

for quantitative test methods, dispersion of results of replicate measurements obtained under specified conditions

Project: EP19

NOTE: It is expressed numerically as the standard deviation or the coefficient of variation.


imprecision

for quantitative measurement procedures, dispersion of independent results of measurements obtained under specified conditions

Project: NBS05

NOTE: Imprecision is expressed numerically as the standard deviation or the coefficient of variation (standard deviation divided by the mean measurement procedure result).


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 or more variants on the same parental gene

Project: NBS05

NOTE: Two or more variants in the cystic fibrosis transmembrane conductance regulator gene on a single allele of chromosome 7


in control

characterization of a process when results from a control sample or a series of control samples are within the acceptable control range

Project: POL1/2


in silico

an analysis performed on a computer or through computer simulation

Project: MM22, MM24


in silico

a biological experiment or simulation performed on a computer

Project: C64


in trans

two variants on different parental genes

Project: NBS05

NOTE 1: Variants in the cystic fibrosis transmembrane conductance regulator gene are on different alleles of chromosome 7; NOTE 2: Parental alleles can contain more than one variant.


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

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

a device intended by the manufacturer for in vitro examination of specimens derived from the human body solely or principally to provide information for diagnostic, monitoring, or compatibility purposes

Project: MM09, MM17

NOTE: Like other medical devices, in vitro diagnostic devices are subject to regulatory approval by national and international authorities.


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 defines in vitro diagnostic 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, 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 US Food and Drug Administration regulates in vitro diagnostic devices, and these are subject to premarket and postmarket controls.


in vitro diagnostic device

term used to describe reagents, instruments, and systems intended for use in the diagnosis of disease or other conditions, including a determination of the state of health, 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: MM22


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)

Alternate Term: IVD instrument

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 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, ISO 18113-1, H26, EP23


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 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 mobile application

an application installed on a mobile device that allows an in vitro diagnostic system to be monitored and controlled

Project: AUTO11


in vitro diagnostic product

chemical, biological, or immunological components, solutions, or preparations intended by the manufacturer to be used as an IVD medical device (adapted from EN375.2001, §3.9)

Project: EP25

NOTE: For the purposes of EP25, “IVD product” also includes reagents, calibrators, controls, diluents


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 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)

Alternate Term: IVD reagen