The International Dairy Federation (IDF/FIL) empirically validates standard microbiological methods for the international dairy industry by using groups of qualified experts. Typically, a logical progression of interlaboratory performance studies conducted by several laboratories leads to a validated method. Control of dairy food matrices and analytes in interlaboratory studies, however, is not rigid. Interlaboratory reproducibility is not usually considered of paramount importance because of the difficulty of establishing test sample homogeneity with low numbers of microorganisms. However, the recent Listeria monocytogenes standard was validated by testing identical inoculated samples after preliminary interlaboratory studies. In the past, IDF/FIL preferred to validate only conventional methods that are widely used in dairy microbiology laboratories rather than novel vapid commercial kit methods. IDF/FIL Standards are internationally recognized.
