Validating rapid micro methods

In 2000, the Parenteral Drug Association (PDA) published the first guidance document on how to validate and implement alternative rapid microbiological methods.

validating rapid micro methods-24validating rapid micro methods-82

One example of a direct measurement method combines fluorescent labeling and laser scanning cytometry to enumerate organisms.

The sample containing microorganisms is filtered onto a membrane and treated with a combination of stains to fluorescently label viable organisms without the need for growth.

Growth-based methods detect a signal after a short incubation period in liquid or on solid media; examples include detection of CO production by colorimetric methods or a change in head space pressure and detection of adenosine triphosphate (ATP) by bioluminescence.

Direct measurement methods can detect cell viability without requiring growth of the microorganism.

One example is amplification of DNA or RNA by polymerase chain reaction (PCR).

RMMs can be qualitative (presence/absence) or quantitative (enumeration), destructive or nondestructive, and can be applied to filterable or non-filterable products.

A bioluminescent enzyme reagent is then applied, which reacts with the ATP to produce light (photons).

The membrane is moved to the detection tower where image processing takes place. Riley, B., A Regulators View of Rapid Microbiology Methods.

The photons are converted into electrons and multiplied in the photomultiplier tube (PMT). European EMD Millipore has developed the Milliflex® Rapid Microbiology Detection System, intended for the rapid detection, response, and resolution of microbial contamination in filterable samples throughout the manufacturing process.

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