Molecular in vitro diagnostic examinations—Specifications for pre-examination processes for venous whole blood—Part 3: Isolated circulating cell free DNA from plasma
GB/T 43279.3-2023 Molecular in vitro diagnostic examinations - Specifications for pre-examination processes for venous whole blood - Part 3: Isolated circulating cell free DNA from plasma
1 Scope
This document provides recommendations and requirements on the handling, storage, processing and documentation of venous whole blood specimens intended for circulating cell free DNA (ccfDNA) examination during the pre-examination phase before an analytical test is performed. This document covers specimens collected in venous whole blood collection tubes.
This document is applicable to any molecular in vitro diagnostic examination performed by medical laboratories. It is also intended to be used by laboratory customers, in vitro diagnostics developers and manufacturers, biobanks, institutions and commercial organizations performing biomedical research, and regulatory authorities.
Different dedicated measures are taken for stabilizing blood genomic DNA, which are not described in this document. Blood genomic DNA is covered in ISO 20186-2.
Different dedicated measures are taken for preserving DNA in circulating exosomes, which are not described in this document.
Note: ccfDNA obtained from blood by the procedures cited in this document can contain DNA originally present in exosomes.
DNA in pathogens present in blood is not covered by this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 22576.1-2018 Medical laboratories - Requirements for quality and competence - Part 1:General requirements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
——ISO Online browsing platform: available at https: //www .iso .org/obp
——IEC Electropedia: available at http: //www .electropedia .org/
3.1
analyte
component represented in the name of a measurable quantity
[SOURCE: GB/T 21415-2008, 3.2, modified.]
3.2
backflow
flow of a liquid opposite to the usual or desired direction
3.3
blood collection set
intravenous device specialized for venipuncture consisting of a stainless steel beveled needle and tube (tubing) with attached plastic wings and fitting connector
Note: The connector attaches to an additional blood collection device, e.g. a blood collection tube.
3.4
blood collection tube
tube used for blood collection, usually with a vacuum which forces blood from the vein through the needle into the tube
3.5
ccfDNA
Circulating cell free DNA
extracellular human DNA present in blood and plasma
Note: ccfDNA can include DNA present in vesicles such as exosomes.
3.6
CcfDNA profile
circulating cell free DNA profile
amount of different ccfDNA molecules, present in blood and plasma that can be measured in the absence of any losses, inhibition and interference
3.7
closed system
non-modifiable system provided by the vendor including all necessary components for the pre-examination and/or examination (i.e. hardware, software, procedures and reagents)
3.8
deoxyribonucleic acid; DNA
polymer of deoxyribonucleotides occurring in a double-stranded (dsDNA) or single-stranded (ssDNA) form
[SOURCE: SN/T 2102.1-2008, 3.1.2]
3.9
Deoxyribonuclease, DNase
enzyme that catalyzes the degradation of DNA into smaller components
3.10
examination
analytical test
set of operations having the object of determining the value or characteristics of a property
Note: Processes that start with the isolated analyte and include all kinds of parameter testing or chemical manipulation for quantitative or qualitative examination.
[SOURCE: GB/T 22576.1-2018, 3.7, modified.]
3.11
examination performance
analytical test performance
analytical performance
ability of an examination procedure to measure or detect a particular analyte
Note 1: Analytical performance is determined from analytical performance studies used to assess the ability of an in vitro diagnostic examination procedure to measure or detect a particular analyte.
Note 2: Analytical performance includes such characteristics as analytical sensitivity, detection limit, analytical specificity (interference and cross-reactivity), trueness, precision and linearity.
[SOURCE: GB/T 39367.1-2020, 3.2, modified.]
3.12
examination provider
analytical test provider
entity that provides the specific analytical test
3.13
needle holder
barrel used in routine venipuncture procedures to hold the blood collection tube in place and to protect the phlebotomist from direct contact with blood
3.14
pre-examination processes
preanalytical phase
preanalytical workflow
processes that start, in chronological order, from the clinician's request and include the examination request, preparation and identification of the patient, collection of the primary sample(s), transportation to and within the medical laboratory, isolation of analytes, and end when the analytical examination begins
Note: The pre-examination phase includes preparative processes, e.g. ccfDNA isolation procedures, which influence the outcome of the intended examination.
[SOURCE: GB/T 22576.1-2018, 3.15, modified.]
3.15
primary sample
specimen
discrete portion of a body fluid, breath, hair or tissue taken for examination, study or analysis of one or more quantities or properties assumed to apply for the whole
[SOURCE: GB/T 22576.1-2018, 3.16, modified.]
3.16
proficiency testing
evaluation of participant performance against pre-established criteria by means of inter-laboratory comparisons
[SOURCE: GB/T 27043-2012, 3.7, modified.]
3.17
ribonucleic acid; RNA
polymer of ribonucleotides occurring in a double-stranded or single-stranded form
[SOURCE: SN/T 2102.1-2008, 3.1.3]
