ISO 6887-1-2017 PDF

Full title and description

Microbiology of the food chain — Preparation of test samples, initial suspension and decimal dilutions for microbiological examination — Part 1: General rules for the preparation of the initial suspension and decimal dilutions (ISO 6887-1:2017). This International Standard defines general, aerobic rules and practical guidance for selecting test portion sizes, preparing initial suspensions (primary dilutions) and producing decimal dilution series for microbiological examination of products intended for human or animal consumption.

Abstract

ISO 6887-1:2017 provides harmonized, general rules for preparation of test samples, the production of initial suspensions and subsequent decimal dilutions used in microbiological enumeration and certain detection methods. It covers diluent selection and preparation, apparatus and handling, sample homogenization and special considerations for different matrix types, and highlights exclusions where specific methods prescribe preparation procedures. The document is intended to be used together with the specific parts of the ISO 6887 series that address particular product groups.

General information

• Status: Published (current edition confirmed)
• Publication date: 15 March 2017 (ISO 6887-1:2017); Amendment 1 published July 2024.
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 07.100.30 — Food microbiology
• Edition / version: Edition 2 (2017); amended by ISO 6887-1:2017/Amd 1:2024
• Number of pages: Main document: 26 pages (ISO); Amendment 1: 10 pages. National/adopted versions and combined publications may show different page counts.

Scope

Specifies general rules for the aerobic preparation of the initial suspension and for preparing decimal dilutions for microbiological examinations of food and animal feed matrices. ISO 6887-1:2017 is intended as the generic (general) part of the ISO 6887 series; other parts of the series give specific preparation rules for particular product groups. The standard excludes sample-preparation instructions that are already specified in microorganism-specific or method-specific standards and notes where procedures might also affect molecular methods (for example, matrix-associated PCR inhibition).

Key topics and requirements

• Principles for selection of test portion size and representative sampling.
• Preparation, selection and sterilization/performance verification of diluents (e.g., buffered peptone water, peptone salt solutions).
• Methods for making the initial suspension (primary dilution) and producing decimal dilution series for microbiological enumeration.
• Apparatus and equipment recommendations (stomachers, blenders, pipettes), cleaning and sterility considerations.
• Practical procedures for different matrix types (liquids, viscous products, high-fat foods, acidic foods, hard/dry/low‑moisture products, frozen products, multi‑component and packaged items).
• Handling and thawing rules for frozen samples and large frozen pieces/blocks.
• Guidance on pooling/compositing and use of larger test portions for qualitative methods (addressed further in the 2024 amendment).
• Timing, temperature and contamination-control recommendations to preserve sample integrity.
• Notes on limitations and exclusions (cases where specific ISO standards or test methods prescribe alternate preparation steps).

Typical use and users

Used by food and feed microbiology laboratories, quality assurance and R&D teams in food production, contract testing laboratories, regulatory and inspection bodies, method developers and accreditation assessors. It is applied when preparing samples and dilution series prior to microbiological enumeration (e.g., plate counts, most probable number) and for many qualitative detection workflows where the sample preparation is not otherwise prescribed.

Related standards

ISO 6887-1 is the generic part of the ISO 6887 series. Closely related documents include other parts of the series (examples): ISO 6887-2 (meat and meat products), ISO 6887-3 (fish and fishery products), ISO 6887-4 (miscellaneous products), ISO 6887-5 (milk and milk products) and later parts addressing other groups. Other frequently referenced standards in food microbiology workflows include ISO 7218 (general requirements and guidance for microbiological examinations), ISO 11133 (culture media preparation and performance testing), ISO 16140‑2 (method validation protocols), ISO 18593 (surface sampling techniques), ISO 7002 (sampling from a lot) and method-specific documents (for example ISO/TS standards for viral testing) that may provide alternate or additional preparation instructions.

Keywords

sample preparation, initial suspension, decimal dilutions, diluent, food microbiology, test portion, homogenization, stomacher, dilution series, ISO 6887, microbiological enumeration, food testing, feed testing

FAQ

Q: What is this standard?

A: ISO 6887-1:2017 is the general (part 1) International Standard giving rules and practical guidance for preparing test samples, making the initial suspension and producing decimal dilutions for microbiological examination of foods and animal feeds.

Q: What does it cover?

A: It covers selection of test portion size, diluent choice and preparation, apparatus and contamination control, methods for producing primary suspensions and dilution series, and special handling guidance for different matrix types. It excludes preparations that are already defined in microorganism- or method-specific standards.

Q: Who typically uses it?

A: Food and feed microbiology laboratories, industry quality and safety teams, contract testing labs, regulators, accreditation bodies and method developers use it to ensure consistent, reproducible sample preparation prior to microbiological testing.

Q: Is it current or superseded?

A: The 2017 edition (Edition 2) is the current generic part. The previous edition (1999) was superseded by the 2017 edition. An amendment (ISO 6887-1:2017/Amd 1) addressing requirements and guidance on larger test portion sizes for qualitative methods was published in July 2024. (Status described here is current as of 2 March 2026.)

Q: Is it part of a series?

A: Yes — ISO 6887 is a multi‑part series. Part 1 is the general rules; other parts give specific rules for product groups (for example meat, fish, milk and miscellaneous products) and should be used together with Part 1 when applicable.

Q: What are the key keywords?

A: Key keywords include sample preparation, initial suspension, decimal dilutions, diluent, homogenization, test portion, food microbiology, stomacher, ISO 6887 and microbiological enumeration.