MICROVAL - A EUROPEAN APPROACH TO THE CERTIFICATION OF NEW MICROBIOLOGICAL METHODS

In recent years, food microbiologists have seen the development of a r ange of nonstandard methods designed to enumerate or determine the pre sence of various microorganisms in food products. Generally the new me thods are designed to give the microbiologist advantages, such as grea ter automation or faster results, over standard conventional methods. The new methods, however, have often not been thoroughly tested to giv e the end user confidence in the results. In order to generate data to show that new methods give results that are comparable with standard methods, they must be validated. A number of validation schemes have b een developed in various countries throughout the world. There has not , however, been an acceptable scheme recognized throughout Europe. The MicroVal project has been involved in the development of a European m icrobiological method validation and certification scheme; it involves 21 partners from 7 EU member states. New methods that are tested by t he MicroVal system will undergo initial testing in a single expert lab oratory, to establish the test's specificity, limit of detection, rela tive accuracy, sensitivity, and linearity. This testing will be follow ed by a collaborative study in a minimum of eight laboratories, which will be used to determine the test precision, repeatability, and repro ducibility. All results will be assessed by two expert reviewers who w ill recommend or reject the test. Tests that are recommended will be f inally accepted by a MicroVal committee. The committee will pass its c omments to one of several certification bodies (working together throu gh a memorandum of understanding) who will certify that the new method gives results that are equivalent to the reference method used throug hout the validation work. The technical rules that describe the work r equired to certify a method are currently being considered by the Euro pean Committee for Standardisation (CEN), with the objective that the rules will become a CEN standard for the certification of new test met hods. When this objective has been achieved the rules will become an I nternational Standards Organisation (ISO) standard for new test method validation.