Measurement uncertainty in microbiological cultivation methods

Microbiological analyses are carried out on clinical, food, feed and enviro nmental samples. The aims of the analyses are diagnostic or estimation of t he safety or the quality of the sample. Important decisions are made on the basis of microbiological analyses. Little attention, however, is paid to t he uncertainty of measurement of microbiological analyses. In microbiologic al cultivation techniques the result is obtained by counting individual obj ects. The normally low number of counted objects strongly affects the resul t of the analysis and its uncertainty. Because of the importance of the par ticle statistical variation to the uncertainty, the approaches developed fo r chemical analyses are not directly applicable to microbiology. This paper discusses microbial analyses and describes a novel guidance document for t he estimation of measurement uncertainty in culturing methods [I].