SIST-TS CEN ISO/TS 5798:2023

SLOVENSKI STANDARD
01-februar-2023
Diagnostični preskusni sistemi in vitro - Zahteve in priporočila za odkrivanje
koronavirusa (SARS-CoV-2) z metodami amplifikacije nukleinskih kislin (ISO/TS
5798:2022)
In vitro diagnostic test systems - Requirements and recommendations for detection of
severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by nucleic acid
amplification methods (ISO/TS 5798:2022)
In-vitro-Diagnostika-Systeme - Anforderungen und Empfehlungen für Qualitätsverfahren
für den Nachweis des Coronavirus 2 des Schweren Akuten Respiratorischen Syndroms
(SARS-CoV-2) mittels Nukleinsäureamplifikation (ISO/TS 5798:2022)
Systèmes d’essai pour diagnostic in vitro - Exigences et recommandations pour la
détection du coronavirus 2 associé au syndrome respiratoire aigu sévère (SARS-CoV-2)
par des méthodes d’amplification des acides nucléiques (ISO/TS 5798:2022)
Ta slovenski standard je istoveten z: CEN ISO/TS 5798:2022
ICS:
11.100.10 Diagnostični preskusni In vitro diagnostic test
sistemi in vitro systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN ISO/TS 5798
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
November 2022
TECHNISCHE SPEZIFIKATION
ICS 11.100.01
English Version
In vitro diagnostic test systems - Requirements and
recommendations for detection of severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2) by nucleic acid
amplification methods (ISO/TS 5798:2022)
Systèmes d'essai pour diagnostic in vitro - Exigences et In-vitro-Diagnostika-Systeme - Anforderungen und
recommandations pour la détection du coronavirus 2 Empfehlungen für Qualitätsverfahren für den
associé au syndrome respiratoire aigu sévère (SARS- Nachweis des Coronavirus 2 des Schweren Akuten
CoV-2) par des méthodes d'amplification des acides Respiratorischen Syndroms (SARS-CoV-2) mittels
nucléiques (ISO/TS 5798:2022) Nukleinsäureamplifikation (ISO/TS 5798:2022)
This Technical Specification (CEN/TS) was approved by CEN on 21 November 2022 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN ISO/TS 5798:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO/TS 5798:2022 has been prepared by Technical Committee ISO/TC 212 "Clinical
laboratory testing and in vitro diagnostic test systems” of the International Organization for
Standardization (ISO) and has been taken over as CEN ISO/TS 5798:2022 by Technical Committee
CEN/TC 140 “In vitro diagnostic medical devices” the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO/TS 5798:2022 has been approved by CEN as CEN ISO/TS 5798:2022 without any
modification.
TECHNICAL ISO/TS
SPECIFICATION 5798
First edition
2022-04
In vitro diagnostic test systems —
Requirements and recommendations
for detection of severe acute
respiratory syndrome coronavirus 2
(SARS-CoV-2) by nucleic acid
amplification methods
Systèmes d’essai pour diagnostic in vitro — Exigences et
recommandations pour la détection du coronavirus 2 associé au
syndrome respiratoire aigu sévère (SARS-CoV-2) par des méthodes
d’amplification des acides nucléiques
Reference number
ISO/TS 5798:2022(E)
ISO/TS 5798:2022(E)
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO/TS 5798:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Overview . 7
4.1 SARS-CoV-2 . 7
4.1.1 General . 7
4.1.2 Pre-examination . 9
4.1.3 Examination — Overview . 9
4.1.4 Post-examination . 11
4.2 Nucleic acid amplification methods . 11
4.2.1 Reverse transcription qPCR (RT-qPCR) . 11
4.2.2 Reverse transcription digital PCR (RT-dPCR) .12
4.2.3 Isothermal amplification methods .12
5 Laboratory requirements .12
5.1 General .12
5.2 Biosafety requirements . 13
5.2.1 Laboratory area . 13
5.2.2 Risk control . 13
5.2.3 Personal protective equipment (PPE) . 13
5.3 General laboratory set-up .13
5.4 Instrumentation . 14
5.5 Laboratory personnel . 14
6 Design and development .14
6.1 Customer, patient and stakeholder needs . 14
6.2 Intended use of analytical test . 14
6.3 Institutional guideline strategy . 15
6.3.1 Laboratory developed tests (LDTs) versus in vitro diagnostic medical
devices (IVD medical devices) . 15
6.3.2 Emergency use authorization . 15
6.4 Clinical strategy . 15
6.5 Design and development planning . 16
6.5.1 Pre-examination of respiratory specimens for SARS-CoV-2 testing. 16
6.5.2 Examination design specifications (analytical test specifications) .22
6.5.3 Design risk management . 27
6.6 Optimization of reagents and methods .28
6.6.1 Selection of SARS-CoV-2 target sequences .28
6.6.2 Potential impact of variants of concern (VOCs) on the quality of NAAT
diagnostic methods for detecting SARS-CoV-2.28
6.6.3 Selection of amplification methods .28
6.6.4 Design and selection of primers .28
6.6.5 Optimization of the reaction system .29
6.6.6 Determination of cut-off values .29
6.6.7 Verification and validation of test design .29
7 Verification for patient care .31
7.1 General . 31
7.2 Confirmation of analytical performance characteristics . 31
7.2.1 Accuracy . 31
7.2.2 Limit of detection (LOD) . 31
7.2.3 Inclusivity . 32
7.2.4 Specificity . 32
iii
ISO/TS 5798:2022(E)
7.2.5 Robustness . . . 32
7.3 Clinical evidence . 33
8 Validation for patient care . .33
8.1 General consideration . 33
8.2 Clarification of the intended use . 33
8.3 Performance with clinical specimens or samples .34
9 Design transfer to production .34
10 Implementation and use in the laboratory and reporting of results .34
10.1 Implementation and use in the laboratory .34
10.2 Reporting and interpretation of results . 35
11 Quality assurance .36
11.1 Performance monitoring . 36
11.2 Design change including optimization of analytical test .36
11.3 Interlaboratory comparison . 37
Annex A (informative) Nucleic acid amplification techniques .38
Bibliography .41
iv
ISO/TS 5798:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 212, Clinical laboratory testing and in
vitro diagnostic test systems, in collaboration with Technical Committee ISO/TC 276, Biotechnology.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO/TS 5798:2022(E)
Introduction
Coronaviruses are enveloped RNA viruses that are broadly distributed in the animal kingdom. They
have been identified in humans, other mammals, and birds. Coronaviruses were named because the
spike proteins known to facilitate viral attachment and cell entry appear like a halo on the virus surface
when viewed under an electron microscope. Coronaviruses are roughly spherical with a diameter
ranging from 118 nm to 136 nm. The coronavirus genome, which ranges from 26 kb to 32 kb, is the
largest among all RNA viruses, including RNA viruses that have segmented genomes. Until 2019, six
coronaviruses have been associated with human diseases:
— severe acute respiratory syndrome-related coronavirus (SARS-CoV),
— Middle East respiratory syndrome coronavirus (MERS-CoV),
— human coronavirus 229E (HCoV-229E),
— human coronavirus OC43 (HCoV-OC43),
— human coronavirus NL63 (HCoV-NL63), and
[1]
— human coronavirus HKU1 (HCoV-HKU1) .
In 2019, a cluster of patients presenting with a respiratory disease were shown, by sequencing, to be
[2]
infected with a novel coronavirus . The coronavirus associated with this cluster was subsequently
named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by the International Committee
[3]
on Taxonomy of Viruses . SARS-CoV-2 is the seventh coronavirus known to infect humans. The disease
caused by SARS-CoV-2 was designated as coronavirus infectious disease 2019 (COVID-19) by the World
[4]
Health Organization (WHO) .
The host range for SARS-CoV-2 is not yet fully defined. SARS-CoV-2 is a beta-coronavirus. The receptor
for SARS-CoV-2 is the angiotensin-converting enzyme 2 (ACE2). ACE2 is a cell-surface, zinc-binding
carboxypeptidase involved in regulation of cardiac function and blood pressure. It is expressed in
epithelial cells of the lung and the small intestine, which are the primary targets of SARS-CoV-2, as well
as the heart, kidney, and other tissues.
SARS-CoV-2 replicates in the upper and lower respiratory tracts and is transmitted by droplets and
aerosols and most likely other contact with asymptomatic and symptomatic infected persons. The basic
reproduction number (R ) of the original variant is between 2 and 3, but significantly more contagious
[5]
variants have developed. The median incubation period is 5,7 (range 2 to 14) days . Similarly to SARS
and MERS, superspreading events have been reported, with a dispersion parameter (kappa) estimated
at 0,1. Most infections are uncomplicated, and 5 % to 10 % of patients are hospitalized mainly due to
pneumonia with severe inflammation. However, complications include respiratory and multiorgan
failures. Risk factors for the complicated disease increase with age and include hypertension, diabetes,
chronic cardiovascular and chronic pulmonary diseases, and immunodeficiency.
Clinical management of COVID-19 and control of infections and spread of SARS-CoV-2 require effective
and efficient in vitro diagnostics. There are a number of tests and kits in use for the detection of SARS-
CoV-2 and the number of methods will continue to increase. Acceptable design, development and
establishment of quality SARS-CoV-2 diagnostics based on nucleic acid detection methods is critical
to ensure COVID-19 infection control. Establishing indices for conducting comprehensive quality
evaluation of these methods and kits both during development and in routine application will ensure
the accuracy of the test results and support epidemic prevention and control. This document provides
requirements and recommendations to consider for the quality practice of SARS-CoV-2 nucleic acid
amplification methods.
vi
TECHNICAL SPECIFICATION ISO/TS 5798:2022(E)
In vitro diagnostic test systems — Requirements and
recommendations for detection of severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2) by nucleic acid
amplification methods
1 Scope
This document provides requirements and recommendations for the design, development, verification,
validation and implementation of analytical tests for detecting the severe acute respiratory syndrome
coronavirus 2 (SARS-CoV-2) using nucleic acid amplification. It addresses pre-examination, examination
and post-examination process steps for human specimens.
This document is applicable to medical laboratories. It is also intended to be used by in vitro diagnostic
developers and manufacturers, as well as by institutions and organizations supporting SARS-CoV-2
research and diagnostics.
This document does not apply to environmental samples.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
severe acute respiratory syndrome coronavirus 2
SARS-CoV-2
virus that causes coronavirus infectious disease 2019 (COVID-19)
3.2
specimen
primary sample
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
Note 1 to entry: The Global Harmonisation Task Force (GHTF) uses the term specimen in its harmonized guidance
documents to mean a sample of biological origin intended for examination by a medical laboratory.
Note 2 to entry: In some countries, the term “specimen” is used instead of “primary sample” (or a subsample
of it), which is the sample prepared for sending to, or as received by, the laboratory and which is intended for
examination.
[6]
[SOURCE: ISO 15189:2012, 3.16 modified — Note 2 to entry was removed and Note 3 to entry was
renumbered as Note 2 to entry.]
ISO/TS 5798:2022(E)
3.3
sample
one or more parts taken from a primary sample (3.2)
EXAMPLE A volume of serum taken from a larger volume of serum.
[6]
[SOURCE: ISO 15189:2012, 3.24 ]
3.4
reverse transcription
RT
process of making complementary DNA [cDNA (3.6)] from an RNA (3.20) template (3.22), using the
enzymatic activity of a reverse transcriptase associated with one or more oligonucleotide primers
under a suitable set of conditions
[7]
[SOURCE: ISO 16577:2016, 3.180 , modified — Replaced “DNA” with “complementary DNA (cDNA)”.]
3.5
deoxyribonucleic acid
DNA
polymer of deoxyribonucleotides occurring in a double-stranded (dsDNA) or single-stranded (ssDNA)
form
[8]
[SOURCE: ISO 22174:2005, 3.1.2 ]
3.6
complementary DNA
cDNA
single-stranded DNA (3.5), complementary to a given RNA (3.20) and synthesised in the presence of
reverse transcriptase to serve as a template (3.22) for DNA amplification
[9]
[SOURCE: ISO 20395:2019, 3.5 ]
3.7
analytical specificity
capability of a measuring system, using a specified measurement procedure, to provide measurement
results for one or more measurands which do not depend on each other nor on any other quantity in the
system undergoing measurement
Note 1 to entry: Lack of analytical specificity is called analytical interference (see ISO 18113-1:2009, A.3.2).
[10]
[SOURCE: ISO 18113-1:2009, A.3.4 ]
3.8
limit of detection
LOD
measured quantity value, obtained by a given measurement procedure, for which the probability of
falsely claiming the absence of a component in a material is 0,05, given a probability of 0,05 of falsely
claiming its presence
[11]
[SOURCE: ISO/IEC Guide 99:2007, 4.18 , modified — “β, given a probability α” was replaced by “0,05,
given a probability of 0,05” and Notes 1 to 3 to entry were deleted.]
3.9
verification
provision of objective evidence that a given item fulfils specified requirements
[11]
[SOURCE: ISO/IEC Guide 99:2007, 2.44 , modified — EXAMPLES 1 to 3 and Notes 1 to 6 to entry were
deleted.]
ISO/TS 5798:2022(E)
3.10
validation
confirmation, through the provision of objective evidence, that the requirements for a specific intended
use or application have been fulfilled
Note 1 to entry: The word “validated” is used to designate the corresponding status.
[12]
[SOURCE: ISO 9000:2015, 3.8.13 , modified — Notes 1 and 3 to entry were deleted and Note 2 to
entry was renamed Note 1 to entry.]
3.11
amplicon
specific DNA (3.5) fragment produced by a DNA-amplification technology, such as the polymerase chain
reaction (PCR) (3.12)
[13]
[SOURCE: ISO 13495:2013, 3.3.1 ]
3.12
polymerase chain reaction
PCR
enzymatic procedure which allows in vitro amplification of DNA (3.5) or RNA (3.20)
[8]
[SOURCE: ISO 22174:2005, 3.4.1 , modified — “or RNA” added to the end of the definition and “in vitro”
has been unitalicized in accordance with the ISO House Style.]
3.13
reference material
material, sufficiently homogeneous and stable with reference to specified properties, which has been
established to be fit for its intended use in measurement or in examination of nominal properties
[11]
[SOURCE: ISO/IEC Guide 99:2007, 5.13 , modified — Notes 1 to 8 to entry and EXAMPLES 1 to 5 were
deleted.]
3.14
pseudo-virus
virus or virus-like particle that can integrate the envelope glycoprotein of another virus to form a virus
with an exogenous viral envelope, and the genome retains the characteristics of the retrovirus itself
3.15
digital PCR
dPCR
procedure in which nucleic acid templates (3.22) are distributed across multiple partitions of nominally
equivalent volume, such that some partitions contain template and others do not, followed by PCR
(3.12) amplification of target sequences and detection of specific PCR products, providing a count of the
number of partitions with a positive and negative signal for the target template
Note 1 to entry: Nucleic acid target sequences are assumed to be randomly and independently distributed across
the partitions during the partitioning process.
Note 2 to entry: The count of positive and negative partitions is normally based on end point detection of PCR
products following thermal cycling, however real-time qPCR (3.16) monitoring of PCR product accumulation is
additionally possible for some dPCR platforms.
[9]
[SOURCE: ISO 20395:2019, 3.10 ]
ISO/TS 5798:2022(E)
3.16
quantitative real-time PCR
qPCR
enzymatic procedure which combines the in vitro amplification of specific DNA (3.5) or RNA (3.20)
segments with the detection and quantification of specific PCR (3.12) products during the amplification
process
Note 1 to entry: While the PCR is producing copies of the relevant DNA sequence, the fluorescent marker
fluoresces in direct proportion to the amount of DNA present, which can theoretically be back-calculated to infer
the original amount of that particular DNA present in a sample (3.3) prior to initiation of PCR.
[9]
[SOURCE: ISO 20395:2019, 3.25 , modified — “RNA” was added.]
3.17
quantification cycle
C
q
quantitative real-time PCR (qPCR) (3.16) cycle at which the fluorescence from the reaction crosses a
specified threshold level at which the signal can be distinguished from background levels
Note 1 to entry: Quantification cycle is a generic term which includes cycle threshold (C ), crossing point (C ),
t p
take off point and all other instrument specific terms referring to the fractional cycle which is proportional to
the concentration of target in the qPCR assay.
Note 2 to entry: The quantification cycle is based either on a threshold applied to all samples (3.3) or on a
regression analysis of the signal, for each sample.
Note 3 to entry: The quantification cycle is a measure with poor reproducibility and cannot be used when
comparing kit performance.
Note 4 to entry: Laboratory based considerations sometimes lead to selection of a cut-off for the cycle number.
The cut-off cannot be chosen not to have a detrimental influence on available limit of detection (3.8).
Note 5 to entry: C does not apply for digital PCR (3.15) and isothermal amplification methods.
q
[9]
[SOURCE: ISO 20395:2019, 3.8 , modified — Notes 3 to 5 to entry have been added.]
3.18
clinical specificity
diagnostic specificity
ability of an in vitro diagnostic examination procedure to recognize the absence of a target marker
associated with a particular disease or condition
Note 1 to entry: Also defined as “percent negativity” in samples (3.3) where the target marker is known to be
absent.
Note 2 to entry: Clinical specificity is expressed as a percentage (number fraction multiplied by 100), calculated
as 100 × the number of true negative values (TN) divided by the sum of the number of true negative plus the
number of false positive (FP) values, or 100 × TN/ (TN + FP). This calculation is based on a study design where
only one sample is taken from each subject.
Note 3 to entry: The target condition is defined by criteria independent of the examination procedure under
consideration.
[10]
[SOURCE: ISO 18113-1:2009, A.3.16 ]
3.19
clinical sensitivity
diagnostic sensitivity
ability of an in vitro diagnostic examination procedure to identify the presence of a target marker
associated with a particular disease or condition
Note 1 to entry: Also defined as “percent positivity” in samples (3.3) where the target marker is known to be
present.
ISO/TS 5798:2022(E)
Note 2 to entry: Diagnostic sensitivity is expressed as a percentage (number fraction multiplied by 100),
calculated as 100 × the number of true positive values (TP) divided by the sum of the number of true positive
values (TP) plus the number of false negative values (FN), or 100 × TP/(TP + FN). This calculation is based on a
study design where only one sample is taken from each subject.
Note 3 to entry: The target condition is defined by criteria independent of the examination procedure under
consideration.
[10]
[SOURCE: ISO 18113-1:2009, A.3.15 ]
3.20
ribonucleic acid
RNA
polymer of ribonucleotides occurring in a double-stranded or single-stranded form
[8]
[SOURCE: ISO 22174:2005, 3.1.3 ]
3.21
calibrator
measurement standard used for calibration
[9]
[SOURCE: ISO 20395:2019, 3.4 , modified — Note 1 to entry and the EXAMPLE were deleted.]
3.22
template
strand of DNA (3.5) or RNA (3.21) that specifies the base sequence of a newly synthesized strand of DNA
or RNA, the two strands being complementary
[7]
[SOURCE: ISO 16577:2016, 3.206 ]
3.23
saliva
whole saliva
bio-fluid of the mouth composed mainly of secretion originating from the three major salivary glands
(parotids, submandibular and sublingual glands) and from salivary glands present in the oral cavity
[14]
[SOURCE: ISO 4307:2021, 3.15 ]
3.24
reverse transcription polymerase chain reaction
RT-PCR
process that combines RT (3.4) and PCR (3.12) to allow amplification of cDNA (3.6) target as a route to
detect RNA (3.20) templates (3.22)
Note 1 to entry: This can be conducted using various formats. A popular approach uses real time PCR
instrumentation which simultaneously conducts the PCR and the analysis; this is described as reverse
transcription quantitative PCR [RT-qPCR (3.16)].
[9]
Note 2 to entry: Adapted from ISO 20395:2019, 3.31 .
3.25
in vitro diagnostic medical device
IVD medical device
device, whether used alone or in combination, intended by the manufacturer for the in vitro examination
of specimens (3.2) derived from the human body solely or principally to provide information for
diagnostic, monitoring or compatibility purposes and including reagents, calibrators (3.21), control
materials, specimen receptacles, software, and related instruments or apparatus or other articles
[15]
[SOURCE: ISO 17511:2020, 3.21 ]
ISO/TS 5798:2022(E)
3.26
pre-examination processes
processes that include preparation and identification of the patient, collection of the primary specimen(s)
(3.2), transportation to and within the medical laboratory, and isolation of RNA (3.20)
Note 1 to entry: Pre-analysis or pre-analytics are synonymous with pre-examination.
[6]
Note 2 to entry: Adapted from ISO 15189:2012, 3.15 .
3.27
limit of quantification
LOQ
lowest concentration or content of the analyte of interest per defined amount of matrix (3.31) that can
be measured with reasonable statistical certainty consistently under the experimental conditions
specified in the method
Note 1 to entry: Generally expressed in terms of the signal or measurement (true) value that will produce
estimates having a specified relative standard deviation (RSD).
[7]
[SOURCE: ISO 16577:2016, 3.91 ]
3.28
positive PCR control
reliable source of well-characterized positive sample (3.3) material, containing intact target nucleic
acid sequences for PCR (3.12)
[7]
[SOURCE: ISO 16577:2016, 3.150 , modified — Note 1 to entry was deleted.]
3.29
internal inhibition control
material acting as an internal control and obtained during the amplification reaction of the target
fragment by adding DNA (3.5) or primers
Note 1 to entry: This material is clearly different from the target fragment.
[7]
Note 2 to entry: Adapted from ISO 16577:2016, 3.82 .
3.30
laboratory developed test
LDT
test developed (or modified) and used within a single laboratory to carry out testing on samples
(3.3), where the results are intended to assist in clinical diagnosis or to be used in making decisions
concerning clinical management
Note 1 to entry: Laboratory developed test needs to be validated for its intended use before putting into service.
[16]
Note 2 to entry: Adapted from ISO 17822:2020, 3.23 .
3.31
matrix
components of a material system, except the analyte
[17]
[SOURCE: ISO 15193:2009, 3.6 ]
3.32
matrix effect
influence of a property of the sample (3.3), independent of the presence of the analyte, on the
measurement and thereby on the measured quantity value
[18]
[SOURCE: ISO 15194:2009, 3.7 , modified — Notes 1 to 2 to entry and the EXAMPLE were deleted.]
ISO/TS 5798:2022(E)
3.33
no template control
NTC
control reaction containing all reagents except the extracted test sample (3.3) template (3.22) nucleic
acid
Note 1 to entry: This control is used to demonstrate the absence of contaminating nucleic acids. Instead of the
template DNA, for example, a corresponding volume of nucleic acid free water is added to the reaction. The term
“PCR reagent control” is also sometimes used.
[9]
[SOURCE: ISO 20395:2019, 3.20 ]
3.34
loop-mediated isothermal amplification
LAMP
strategy for achieving isothermal DNA (3.5) amplification by utilizing two or three uniquely designed
primer sets and a polymerase with high strand displacement activity
[7]
[SOURCE: ISO 16577:2016, 3.94 ]
4 Overview
4.1 SARS-CoV-2
4.1.1 General
The process of SARS-CoV-2 molecular detection testing using the nucleic acid amplification test (NAAT)
typically includes pre-examination and examination steps. The pre-examination steps include collection
of clinical specimens, transport, storage, sample lysis, and nucleic acid extraction and concentration.
Examination steps include reverse transcription (cDNA synthesis) and an appropriate amplification
method. In addition, post-examination steps such as management of waste and reporting of the test
results are included.
Quality attributes for the NAAT-based detection processes include, but are not limited to, evaluation of
the performance of a suitable extraction procedure, evaluation of test reagents to meet minimum test
criteria, a comprehensive evaluation of the analytical specificity, limit of detection (LOD) of the assay,
and evaluation of the stability of the reagents.
The technical procedure to evaluate the quality attributes is shown in Figure 1, including the whole
process evaluation and the key analytic performance evaluation.
NOTE The nucleic acid extraction part of quality evaluation is not always needed for NAATs where only one
nucleic acid extraction method is used or when the extraction method is an integral part of the workflow.
ISO/TS 5798:2022(E)
Figure 1 — Workflow of quality evaluation of SARS-CoV-2 detection method based on the
nucleic acid amplification test (NAAT)
ISO/TS 5798:2022(E)
4.1.2 Pre-examination
For the detection of SARS-CoV-2, during the pre-examination work process, the following general
considerations should be taken into account:
a) Appropriate personal protective equipment (PPE) should be used.
b) Specimen type selection: SARS-CoV-2 mainly infects the respiratory system; specimen selection
should be determined with reference to the characteristics of SARS-CoV-2-related exposure or
infection.
c) Specimen collection: depending on the selected specimen types, clinical specimens should be
obtained according to standardized sampling requirements.
d) Specimen packaging: specimen packaging should take into account appropriate biosafety practices.
e) Specimen transport and storage: during the transport and storage process, the impact on the
degradation of viral nucleic acid should be taken into account.
f) Inactivation of SARS-CoV-2: before testing in the laboratory, initial processing (before inactivation)
of all specimens should take place in a validated biosafety cabinet (BSC) or primary containment
device. If initial procedures involve manipulation of a primary specimen (e.g. dilution with
inactivating reagent), they should be included in assay verification and validation.
NOTE Further detailed information on pre-examination parameters can be found in 6.5.1.
4.1.3 Examination — Overview
4.1.3.1 General
During laboratory testing of SARS-CoV-2 nucleic acid, the following general considerations should be
taken into account:
a) Appropriate PPE should be used for all examinations.
b) Separate equipment, single use disposables, or both should be used for all activities to avoid cross-
contamination.
c) Sample extraction, reaction reagent preparation, and amplicon handling should be conducted in
separate laboratory rooms.
The need for separate rooms can be somewhat reduced by use of commercially available assays,
closed-tube methods, and automated instruments. The fully automated methods require only
one room or dedicated zone for laboratories using only commerc
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