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Updated: Jan 26, 2026

Determination of Sialic Acids in Liver and Milk Samples of Wild-type and CMAH Knock-out Mice.
Published on: July 14, 2017
Improved Sensitivity of the Bioluminescent Determination of Numbers of Bacteria in Milk Samples
Jo Ann J Webster1, Marliese S Hall1, C Nelson Rich1
1Departments of Biochemistry and Animal Science, Oklahoma State University, Stillwater, Oklahoma 74078-0454.
Abstract:
A procedure was developed for the sensitive measurement of bacterial ATP in raw milk samples using the firefly luciferase assay. A sensitivity of 105 bacteria/ml was achieved in the laboratory. Treatment of milk samples with a detergent (Lubrol PX) and a proteolytic enzyme (trypsin) allowed filtration of 50 ml of milk through a 0.4-μm Nucleopore filter; a 50-ml sample of milk was required to provide sufficient ATP for measurement. The bacterial ATP was released from the bacteria on the filter using the commercial product Nucleotide Releasing Reagent for Bacteria (NRB® from Lumac). The procedure allows determination of 105 bacteria/ml of raw milk in 20 min.
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