DIN EN ISO 16297:2014-09

This International Standard gives guidelines for the evaluation of instrumental alternative methods for total bacterial count in raw milk from animals of different species. Any quantitative measurement in microbiology should consider that there is a requirement for the microbiological state in a sample to be regarded as one point within the co-ordinates of a multidimensional system, which is to be projected on to the one-dimensional scale of the method applied, that is, plate count, flow cytometry. Aspects such as flora (types and numbers of microorganisms and their distribution), growth phase, sub-lethal damage, metabolic activity, and history, influence to a greater or lesser extent any parameter that is measured. It is evident that any projection of an n-dimensional situation on to an one-dimensional scale is bound to provide a picture of the real situation that is rather restricted. In this respect one has to bow to the inevitable, regardless of which method of measurement is preferred. The term reference (or official or anchor) method in this International Standard means a method internationally recognized by experts, used in legislation or by agreement between the parties. There are requirements for evaluation of an alternative method to refer to the reference method and to be based on the examination of suitable samples for its intended use. This document contains without any modification the International Standard ISO 16297:2013 which has been prepared by Subcommittee SC 5 "Milk and milk products" (secretariat: NEN, Netherlands) of Technical Committee ISO/TC 34 "Food products" (secretariat: AFNOR, France). Due to decision of CEN/TC 302 "Milk and milk products - Methods of sampling and analysis" (secretariat: NEN, Netherlands), ISO 16297:2013 is hereby adopted. The committee responsible for this standard is NA 057-01-12 AA "Validierung mikrobiologischer Verfahren" ("Validation of microbiological methods") at DIN.