scope:

The proposed deliverable specifies the procedure for single-laboratory validation of mainly non-proprietary methods in the fields of microbiological analysis of food, feed, and environmental and primary production stage samples. Single-laboratory validation is required if an interlaboratory validation according to ISO 16140-2 is not appropriate, e.g. for in-house methods or when the required number of participating laboratories is not available. Single-laboratory validation is not part of the optimization of methods. It can be applied only for methods that are fully specified with regard to all relevant parameters (including tolerances on temperatures and specifications on nutrient media). The proposed deliverable describes two protocols for single-laboratory validation, a conventional protocol, and a factorial protocol. The conventional protocol is a stepwise procedure; both the study design and the performance measures are derived from ISO 16140-2. The performance measures of the factorial protocol are also derived from ISO 16140-2; however, it is using an orthogonal, factorial study design. 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 individual tests can be reduced by more than 50 %.