Improved Sensitivity of the Bioluminescent Determination of Numbers of Bacteria in Milk Samples.

A procedure was developed for the sensitive measurement of bacterial ATP in raw milk samples using the firefly luciferase assay. A sensitivity of 10 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.