Precision Testing of Standardized Microbiological Methods

    Volume 14, Issue 6 (November 1986)

    ISSN: 0090-3973

    CODEN: JTEOAD

    Page Count: 3


    Beckers, HJ
    Head, Section of Food Hygiene, Laboratory for Water and Food Microbiology, National Institute of Public Health and Environmental Hygiene, Bilthoven,

    (Received 31 October 1985; accepted 21 April 1986)

    Abstract

    Tests performed on identical materials in identical circumstances do not yield identical results. This is attributed to unavoidable random errors inherent in every test procedure. Repeatability and reproducibility have been found sufficient for describing the precision of a method. Examples of interlaboratory precision experiments in the field of food microbiology are presented, which also demonstrate the different types of reference material that can be used. With a fluid, microbiologically stabilized by freezing, repeatability of aerobic and Enterobacteriaceae plate counts (expressed in 10log-units) appeared to be 0.28; reproducibility was 0.37 for both plate counts. The repeatability of Staphylococcus aureus plate counts varied between 0.26 and 0.52, reproducibility between 0.31 and 0.84, depending on the method of enumeration and the testing procedure. It is concluded that microbiological methods should be evaluated by precision tests, carried out on an international scale.


    Paper ID: JTE10349J

    DOI: 10.1520/JTE10349J

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    Author
    Title Precision Testing of Standardized Microbiological Methods
    Symposium , 0000-00-00
    Committee C26