Overview
ISO 16140-3:2021/Amd 1:2025 is an important amendment to the ISO 16140 series, titled Microbiology of the food chain - Method validation - Part 3: Protocol for the verification of reference methods and validated alternative methods in a single laboratory. This amendment specifically introduces the protocol for the verification of validated identification methods of microorganisms within a single laboratory setting.
This international standard, developed by ISO Technical Committee ISO/TC 34 and subcommittee SC 9 in collaboration with the European Committee for Standardization (CEN), ensures consistency and reliability in microbiological analysis of the food chain. It supports laboratories in demonstrating competence and conformity through rigorous method verification, specifically for microbial identification.
Key Topics
- Scope of Verification: Verification focuses on implemented validated identification methods applied to isolated colonies on selective or non-selective agar plates.
- Implementation Verification: Laboratories verify their ability to use the validated method correctly, reviewing validation data and testing colonies from defined agar plates.
- Experimental Design: Selection of strains depends on the method’s scope, with testing based on a defined number of strains (5 to 15), covering genera, families, or species as applicable.
- Strain Selection: Strains should be well-characterized and representative of the relevant biodiversity, sourced from culture collections, laboratory stocks, or commercial reference materials.
- Result Evaluation: Tabulated results show identification agreements (IA), deviations (ID), or no identification (N), providing clarity on the method’s accuracy.
- Acceptability Criteria: Verification requires 100% agreement of actual results with expected microbial identity to confirm method validity.
- Root Cause Analysis: Non-conformance triggers a root cause analysis addressing possible causes like laboratory errors, media formulation issues, or incorrect strain identities.
- Definitions Added: Key terms include identification agreement, assigned identity, deviation, and identification method, crucial for uniform understanding.
- Annex G: Provides practical examples of verification processes for identification methods applied to multiple genera within a family using selective agar.
Applications
- Food Safety Laboratories: Enables reliable microbial identification, critically supporting detection of pathogens or spoilage organisms in food products.
- Quality Control: Confirms validated methods perform correctly, ensuring consistent and legally defensible microbiological results.
- Method Implementation: Supports laboratories transitioning validated identification technologies such as molecular or proteomic approaches (PCR, DNA sequencing, mass spectrometry).
- Regulatory Compliance: Aligns with international requirements for method validation and verification, facilitating global trade and public health protections.
- Research and Development: Assists in validating innovative identification methods before routine laboratory use, optimizing accuracy in microbial taxonomy.
Related Standards
- ISO 16140 Series: Covers method validation and verification in microbiology of the food chain, including:
- Part 2: Protocol for the validation of alternative methods.
- Part 6: Confirmation methods validation.
- Part 7: Validation of identification methods of microorganisms (specifically addresses methods lacking reference methods).
- ISO 17468:2023: Defines reference methods within microbiological standards.
- ISO 23418: Concerning whole-genome sequencing (WGS) as a future reference method.
- ISO 21528-2: Relates to confirmation procedures of Enterobacteriaceae.
- ISO 10272-1 and ISO 10272-2: Reference methods for Campylobacter spp. detection and identification.
This amendment strengthens the framework for microbiological method validation by focusing on verified identification protocols for microorganisms, thus enhancing laboratory confidence in results critical for food safety, quality assurance, and regulatory compliance. Implementing ISO 16140-3:2021/Amd 1:2025 ensures rigorous adherence to validated techniques, improving reliability in the microbiological analysis of the food chain.