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

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.

absorbance

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

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, A⁵⁴⁰_HiCN = absorbance of hemiglobincyanide at 540 nm.

absorptance

the radiant power absorbed by a system

Project: NRSCL8

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

absorption

a 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.

absorption

a taking in or reception by physicochemical action

Project: NRSCL8

absorptivity

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

Project: I/LA24

absorptivity

(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 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

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 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

(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

closeness of agreement between a test result and the true 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; NOTE 3: Accuracy of a measurement is defined as the closeness of agreement between a measured quantity value and a true quantity value of a measurand (JCGM 200:2012).

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

(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

(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

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 Subchapter 4.5 of CLSI 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

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.

adsorption

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

Project: NRSCL8

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

Project: EP19

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

advisory notice

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

Project: ISO 18113-1

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

aerosol

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

Project: M29

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

aerosols

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

Project: POL1/2, ISO 15190

aerosols

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

Project: QMS04

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

aerotolerant

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

Project: M56

affinity

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

Project: I/LA20, I/LA34

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

affinity

the force of attraction between molecules

Project: I/LA30

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 K_a and R_f (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 α_IIb 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

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

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

Project: NRSCL8

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

aliquot

a portion of 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

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

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 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

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.

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.

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

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

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 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 (d_alt)

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 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

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

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, 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

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 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 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 E–detecting 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 E–detecting 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 E–detecting assays; NOTE 8: The term “allergen-related analytical specificity (selectivity)” is particularly useful to understand and justify the concept of species-specific vs crossreactive 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, 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: PRE02

anion 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: 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

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

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

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

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

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

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

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

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 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

an agent that prevents the coagulation of blood or blood products

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

anticoagulant

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

Project: H58, MM17, H59

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

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

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 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

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

Project: I/LA24

autofluorescence

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

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.

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

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

net affinity of all binding sites of antibodies

Project: I/LA30

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

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 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 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

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

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 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

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 can 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 CLSI EP35, bias refers to the estimated bias at specific concentrations from a measurement procedure equivalence study; NOTE 8: In CLSI EP35, the metrological term systematic difference is related to the term “bias.”

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

(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

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

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.

binding capacity

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

Project: DI01

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 or their environment

Project: AST02, HS02, POCT10, POCT04

biohazard

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

Project: QMS04

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

See microbiological safety cabinet

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

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 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

a specific analyte (eg, 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

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

(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

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

(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

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

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

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

Project: M28

blood

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

Project: ISO 17593, POCT04

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

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

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

(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

(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

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.

blood specimen

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

Project: POCT13, POCT17

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 (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: M100, 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 outcomes.

breakpoint

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

Project: VET09

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 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 antimicrobial susceptibility test conducted using serial concentrations of an antimicrobial agent incorporated into a broth growth medium, in separate test tubes or in the wells of a microtitration tray

broth dilution susceptibility test

an in vitro antimicrobial susceptibility test conducted using serial concentrations of an antimicrobial agent incorporated in liquid nutrient media that are inoculated with a bacterial suspension to determine the minimal inhibitory concentration of an antimicrobial agent

Project: VET05

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

broth microdilution technique

the method of antimicrobial susceptibility testing that is based on preparation of a liquid broth medium containing various concentrations of antimicrobial agents into which a defined inoculum of microorganisms is inoculated and then incubated and observed for growth

Project: M43

bubble diagram

graphic illustration, using circles, of the required relationships between various spaces in a project

Project: QMS04

buffer

a solution or reagent that can resist a change in pH upon addition of either an acid or a base

Project: MM04, I/LA28

buffy coat

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.

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

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

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

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

Project: ISO 18113-1

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

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

calibrator

See calibration material

Project: I/LA34

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 CLSI 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

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 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

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 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

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 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: N_CA × 100/N,whereN_CA 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: N_CA • 100/N where: N_CA 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 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 sample that IS smeared across a glass microscope slide for subsequent staining and microscopic examination

Project: MM23

NOTE: Cell cytology samples also can 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

cellulose acetate membrane

a reverse osmosis membrane constructed of cellulose diacetate/triacetate

Project: GP40

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

fluid within the ventricles of the brain and the subarachnoid space

Project: H56

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

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 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 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 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

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 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

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 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 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 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

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 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 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).