ISO 22174:2024

Microbiology of the food chain — Polymerase chain reaction (PCR) for the detection and quantification of microorganisms — General requirements and definitions

This document specifies the general requirements for the in vitro amplification of nucleic acid sequences (DNA or RNA). This document is applicable to the testing for microorganisms and viruses from the food chain using the polymerase chain reaction (PCR). This document, or parts of it, is applicable to other fields of PCR diagnostics based on a case-by-case evaluation. The minimum requirements laid down in this document are intended to ensure that comparable and reproducible results are obtained in different laboratories. This document has been established for microorganisms from the food chain and is applicable to: — products intended for human consumption; — products for feeding animals; — environmental samples in the area of food and feed production and handling; — samples from the primary production stage.

Microbiologie de la chaîne alimentaire — Réaction de polymérisation en chaîne (PCR) pour la recherche et la quantification de micro-organismes — Exigences générales et définitions

General Information

• Status: Published
• Publication Date: 15-Aug-2024
• ICS: 07.100.30 - Food microbiology
• Technical Committee: ISO/TC 34/SC 9 - Microbiology
• Drafting Committee: ISO/TC 34/SC 9 - Microbiology
• Current Stage: 6060 - International Standard published
• Start Date: 16-Aug-2024
• Due Date: 22-Dec-2023
• Completion Date: 16-Aug-2024

Relations

• Consolidates: ISO 683-5:2017 - Heat treatable steels, alloy steels and free-cutting steels — Part 5: Nitriding steels
• Effective Date: 06-Jun-2022
• Revises: ISO 20837:2006 - Microbiology of food and animal feeding stuffs — Polymerase chain reaction (PCR) for the detection of food-borne pathogens — Requirements for sample preparation for qualitative detection
• Effective Date: 06-Jun-2022
• Revises: ISO 22174:2005 - Microbiology of food and animal feeding stuffs — Polymerase chain reaction (PCR) for the detection of food-borne pathogens — General requirements and definitions
• Effective Date: 06-Jun-2022
• Revises: ISO 20838:2006 - Microbiology of food and animal feeding stuffs — Polymerase chain reaction (PCR) for the detection of food-borne pathogens — Requirements for amplification and detection for qualitative methods
• Effective Date: 06-Jun-2022
• Revises: ISO 22119:2011 - Microbiology of food and animal feeding stuffs — Real-time polymerase chain reaction (PCR) for the detection of food-borne pathogens — General requirements and definitions
• Effective Date: 06-Jun-2022

Standards Content (Sample)

International
Standard
ISO 22174
Second edition
Microbiology of the food chain —
2024-08
Polymerase chain reaction (PCR)
for the detection and quantification
of microorganisms — General
requirements and definitions
Microbiologie de la chaîne alimentaire — Réaction de
polymérisation en chaîne (PCR) pour la recherche et la
quantification de micro-organismes — Exigences générales et
définitions
Reference number
© ISO 2024
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ii
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General terms .2
3.2 Terms related to the extraction and purification of DNA/RNA .3
3.3 Terms related to reverse transcription of RNA to DNA .4
3.4 Terms related to DNA amplification by PCR/RT-PCR .4
3.5 Terms related to controls .5
3.6 Terms related to qPCR .6
3.7 Terms related to dPCR .7
4 Principle . 8
4.1 General .8
4.2 Laboratory sample .9
4.3 Sampling, transport and storage.9
4.4 Preparation of test sample .9
5 Microbial enrichment and virus concentration . 9
5.1 Microbial enrichment .9
5.2 Virus concentration .9
6 Nucleic acid preparation . 10
6.1 General .10
6.2 Prevention of amplification of DNA from dead cells .10
6.3 Nucleic acid extraction, release and purification .10
6.4 Nucleic acid quality and quantity .10
7 PCR amplification . .11
8 Detection and confirmation of amplicons .11
9 General environmental laboratory requirements .12
9.1 General . 12
9.2 Laboratory setup . 12
9.2.1 General . 12
9.2.2 Control of flows . 13
9.2.3 Cleaning of laboratory .14
9.2.4 Environmental monitoring for nucleic acid contamination .14
10 Reagents and consumables . 14
11 Equipment . 14
12 Procedure .15
12.1 Enrichment and sample treatment . 15
12.2 Amplification .16
12.2.1 General .16
12.2.2 Control reaction .16
12.2.3 Detection of amplicon .18
12.2.4 Data analysis .18
12.3 Evaluation .19
12.3.1 Qualitative evaluation .19
12.3.2 Quantitative evaluation . 20
12.4 Test report .21
13 Performance characteristics of PCR-based methods .21
14 Validation and verification of PCR-based methods.21
14.1 General .21

iii
14.2 Validation .21
14.3 Verification . . 22
Annex A (informative) Fluorescence signals and amplification curve .23
Bibliography .26

iv
Foreword
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This document was prepared by Technical Committee TC 34, Food products, Subcommittee SC 9, Microbiology,
in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 463,
Microbiology of the food chain, in accordance with the Agreement on technical cooperation between ISO and
CEN (Vienna Agreement).
This second edition cancels and replaces ISO 22174:2005, ISO 20837:2006, ISO 20838:2006 and
ISO 22119:2011, which have been technically revised.
The main changes are as follows:
— inclusion of requirements for the implementation of digital PCR;
— inclusion of requir
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