DIN EN ISO 16140-5:2018-02

The proposed deliverable specifies an alternative technical protocol for the validation of mostly non-proprietary methods in the field of microbiological analysis of food, animal feed, and environmental and primary production stage samples. It is closely related to ISO 16140-2. The latter specifies the technical protocol for the validation of proprietary methods, including a classical interlaboratory study and a method comparison study to be conducted in one laboratory. The realization of classical interlaboratory studies demands a sufficient number of participating laboratories (at least 8 laboratories are required). There are many occasions where a sufficient number of participating laboratories is not available (e. g. when a new method is required quickly after an outbreak of a new microorganism). In this case, the validation cannot be considered as reliable any longer. The proposed deliverable uses a modified protocol based on orthogonal, factorial studies. By selection of suitable influencing factors (technician, nutrient media, sample preparation, temperature, duration) a high certainty of the determined method validation parameters is obtained, so that the number of required collaborating laboratories can be reduced up to a minimum of 4. This validation protocol can be used in different ways. If the 4 collaborators can be considered a 'random sample' of independent and competent laboratories and from different organizations, the test method can be considered as being validated in the sense that accurate and precise measurements are to be expected from any competent laboratory. If the 4 collaborators can be considered a 'random sample' of independent and competent laboratories from one organization, the test method can be considered as being validated in the sense that accurate and precise measurements are to be expected from any competent laboratory in this organization.