Andrades peptone water, 500g

Product detailed description

Andrade’s indicator is a solution of acid-Fuchsin that when added to peptone water is colorless or slightly pink at pH 7.4. It becomes pink at acid pH levels and yellow at alkaline pH levels (working over a pH range of 5-8). The peptone used in this medium is free from fermentable carbohydrates and also free from nitrates which may interfere with gas production.

• description:  peptone water Andrade's
• product type: pre-enrichment Medium
• quantity: 500 g
• yield: for 33,3 L medium

The biochemical identification of organisms capable of growing in this medium is made by observing the catabolism of the various carbohydrates added to separate tubes of peptone water. To detect fermentation, which is the production of acid and gas, a small, inverted tube (Durham fermentation tube) is inserted into the peptone water to trap any gas produced by the organism. A single bubble in the tube is sufficient to label the organism positive. Some organisms will utilize the sugar to produce acid only, without gas formation.

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