High grade Andrade peptone water is supplied by Micromaster. It is available in the form of a cream to yellow coloured with pink tinge, homogeneous free flowing powder. For maximum efficiency, it must be stored below 30C in tightly closed container. Andrade Peptone Water is a basal medium to which various carbohydrates can be added to study fermentation reactions, particularly of members of the Enterobacteriaceae.

Quantity provided: 100 g/pack

Carbohydrate fermentation reactions helps identifying and differentiating various bacteria. Andrade Peptone Water is the most commonly used media for carbohydrate fermentation. Desired carbohydrate is added to the medium, which is inoculated with the test organism. If the test organism metabolizes the added carbohydrate, acids are produced, thereby lowering the pH of the medium. This causes a subsequent colour change of the indicator, from colourless to pink to red. If the added carbohydrate is not metabolized, the medium remains pale tan to straw coloured. Gas produced during fermentation is collected in the Durhams tube.

The peptic digest used in the medium is free from fermentable carbohydrates and the medium is also free from nitrates which may interfere with gas production. Andrade indicator is a solution of acid fuchsin which when titrated with sodium hydroxide; changes colour from pink to yellow. The Andrade indicator changes colour from yellow to pink as the pH decreases. The medium is pink when hot but becomes straw coloured on cooling. The biochemical identification of organisms capable of growing in this medium is made by various sugar fermentation results.