Overview
EN ISO 22174:2024 (ISO 22174:2024) - titled Microbiology of the food chain - Polymerase chain reaction (PCR) for the detection and quantification of microorganisms - General requirements and definitions - sets out the general requirements and definitions for in vitro amplification of nucleic acids (DNA/RNA) used to detect and quantify microorganisms and viruses in the food chain. Published by CEN/ISO in 2024, it supersedes the 2005 edition and aims to ensure comparable, reproducible PCR results across laboratories testing products for human consumption, animal feed, environmental samples related to food/feed production, and primary production-stage samples.
Key Topics
- Scope & definitions: Unified terminology covering extraction, reverse transcription (RT-PCR), qPCR, dPCR and controls.
- Sampling, transport & storage: Requirements for laboratory samples and pre-analytical handling to preserve nucleic acid integrity.
- Sample preparation: Guidance on preparation, microbial enrichment and virus concentration strategies when applicable.
- Nucleic acid preparation: Extraction, purification, assessment of nucleic acid quality/quantity and measures to prevent amplification from dead cells.
- Amplification and detection: PCR/RT-PCR workflows, qPCR and dPCR considerations, detection and confirmation of amplicons, and interpretation of amplification curves.
- Laboratory environment: Layout, flow control, cleaning, and environmental monitoring to control nucleic acid contamination.
- Reagents, equipment & controls: Minimum requirements for consumables, instruments, and internal/external controls to ensure assay reliability.
- Data analysis & reporting: Qualitative and quantitative evaluation, performance characteristics, and reporting requirements.
- Validation & verification: Framework for method validation, verification and performance assessment.
- Annexes: Informative material (e.g., fluorescence signals and amplification curve interpretation).
Applications and Users
This standard is designed for practical use by:
- Food and feed microbiology laboratories performing PCR/qPCR/dPCR testing
- Public health and veterinary diagnostic labs monitoring pathogens in the food chain
- Environmental testing teams in food production and processing facilities
- Test kit and assay developers, and instrument manufacturers
- Regulatory agencies and accreditation bodies ensuring consistent method performance
Benefits include improved reproducibility, harmonized terminology, contamination control, and clearer validation/verification pathways for PCR-based diagnostics in food safety contexts.
Related Standards
EN ISO 22174:2024 complements other laboratory and food-microbiology guidance, including laboratory accreditation standards (e.g., ISO/IEC 17025) and ISO methods for food microbiology and method validation. Implementers should align PCR workflows with applicable national and sector-specific requirements.
Keywords: EN ISO 22174:2024, ISO 22174:2024, PCR detection and quantification, food chain microbiology, qPCR, dPCR, nucleic acid extraction, validation, laboratory setup, contamination control.