EN ISO 21528-1:2017

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Diluent, culture media and reagent
6 Equipment and consumables
7 Sampling
8 Preparation of test sample
9 Procedure
10 Expression of results
11 Precision
12 Test report
13 Quality assurance
Annex A (informative) - Enumeration by MPN technique
Annex B (normative) - Culture media and reagents
Annex C (informative) - Method validation studies and
        performance characteristics
Bibliography

ISO 21528-1:2017 specifies a method, with enrichment, for the detection of Enterobacteriaceae. It is applicable to- products intended for human consumption and the feeding of animals, and- environmental samples in the area of primary production, food production and food handling.This method is applicable- when the microorganisms sought are expected to need resuscitation by enrichment, and- when the number sought is expected to be below 100 per millilitre or per gram of test sample.A limitation on the applicability of ISO 21528-1:2017 is imposed by the susceptibility of the method to a large degree of variability (see Clause 11).NOTE Enumeration can be carried out by calculation of the most probable number (MPN) after incubation in liquid medium. See Annex A.