The Comparative Value of Quantitative and Qualitative Bacteriological Methods as Applied to Milk, with Especial Consideration of the Methylene Blue Reduction Test

Summary The advantages and disadvantages of the various methods of determining the number of bacteria in milk are discussed as to their applicability to raw and pasteurized milk for the purpose of determining the past history of the milk, its future history, or for control purposes either in the milk plant or by the health officials. Original data are presented which show that the methylene blue reduction test measures with a high degree of accuracy the bacterial content of milk when applied to samples of milk, the bacterial content of which has been varied by the addition of different amounts of the same inoculum.