ISO 16140-7:2024

Overview

ISO 16140-7:2024 - "Microbiology of the food chain - Method validation - Part 7: Protocol for the validation of identification methods of microorganisms" provides a standardized protocol for validating microbial identification methods used in food- and feed-related microbiology when no single reference method exists. The standard sets out general principles, technical procedures and evaluation criteria to demonstrate the performance and reliability of identification workflows (e.g., molecular assays, mass spectrometry, sequencing) using well-defined strains and controlled study designs.

Key topics and technical requirements

• Scope: Applies to identification of microorganisms (bacteria and fungi) from isolated colonies recovered from products for human consumption, animal feed, environmental samples in food/feed production and primary production samples.
• Validation approach: Because no reference method is available, validation is based on testing well-characterized strains rather than method comparison studies.
• Method specification: Validation must describe the method concept, limitations, identification database/algorithm (when applicable) and the agar(s) from which colonies are identified.
• Strain selection and testing: The standard details requirements for selection, number and testing of strains to assess identification reliability (see clauses on strains and Annex B for selection considerations).
• Performance characteristics: Defines how to evaluate identification reliability, expression and interpretation of results, and how to deal with inconclusive or ambiguous identifications.
• Interlaboratory study: Provides a protocol for multi-laboratory studies (data sets to collect, study conduct, expression of results and interpretation) to demonstrate reproducibility and robustness across labs.
• Supporting material: Informative annexes include guidance for ecosystems, result expression/interpretation and illustrative examples (Annex A, C, D) and a normative annex for strain selection (Annex B).
• Limitations: Identification methods validated under ISO 16140-7 cannot replace mandatory confirmation procedures in reference methods or alternative methods validated under ISO 16140-2 or ISO 16140-6; where confirmation is required, identification methods may be used as additional information only.

Applications and who uses it

• Method developers and manufacturers of identification kits (PCR assays, MALDI-TOF libraries, sequencing workflows) to demonstrate method performance prior to commercialization.
• Food and feed testing laboratories and reference/regulatory labs validating new identification workflows for routine use or accreditation.
• Accreditation bodies and proficiency-test organizers assessing method robustness and interlaboratory reproducibility.
• Researchers designing validation studies for microbial identification in food-chain contexts.

Related standards

• ISO 16140 series (Parts 1–6) - method validation and verification frameworks
• ISO 23418 - whole-genome sequencing (WGS) guidance (emerging reference method)
• ISO 17468 - development and validation of standardized methods

Keywords: ISO 16140-7, method validation, identification methods, microbiology of the food chain, identification reliability, interlaboratory study, strain selection, food safety.