PURPLE BROTH BASE

Purple Broth Base is used for studying carbohydrate fermentation reactions, particularly in the identification of gram-negative enteric bacteria on addition of the desired carbohydrate. Purple media were originally formulated by Vera. This medium is recommended by FDA for fermentation studies of sugars.
The carbohydrates they utilize and the types and quantities of acid they produce differentiate bacteria. These differences in enzymatic activity serve as one of the important characteristics in differentiation of bacterial species. The principle of carbohydrate fermentation states that the action of organism on a carbohydrate substrate results in acidification of the medium, detected by a pH indicator dye.

for identi?cation of pure cultures of enteric and other microorganisms