Alkaline Peptone Water is supplied by HiMedia. It is a sterile ready prepared media containing 5ml of light yellow coloured clear solution in bottles. Alkaline Peptone Water is generally used for the enrichment of Vibrio species. It is advisable to store this ready prepared media between 2-8C. Composition (in gm/L) is as follows:

Peptic digest of animal tissue (10.00)

Sodium chloride (10.00)

It is advisable to inoculate clinical materials containing small numbers of Vibrio into an enrichment medium prior to plating onto a selective medium like TCBS Agar. Alkaline Peptone Water is suitable for this purpose. The relatively high pH of the medium (approximately 8.4) provides a favourable environment for the growth of Vibrio' s. This medium is recommended by APHA for enrichment of Vibrio species from seafood, infectious materials and other clinical specimens such as faeces. Peptic digest of animal tissue provides amino acids and other nitrogenous substances. Sodium chloride maintains osmotic equilibrium. Growth in tubes is indicated by turbidity compared to an un-inoculated tube (control). Growth from the enrichment broth is used for plating on selective media. For biochemical identification a pure culture is recommended.