for selective isolation of Vibrio cholerae and other enteropathogenic Vibrio's. It is recommended by BIS committee under specification IS: 5887 (Part V) 1976, reaffirmed 2005. TCBS AGAR ishighly selective for the isolation of Vibrio choleraeandV.parahaemolyticusfrom stool specimens, and specified in standard methods for food testing as per recommended by BIS. This highlyselective medium meets the nutritional requirements of Vibriospp., and allows competing with intestinal flora. Vibriospp. isable to grow in media containing increased salt concentrations. Vibrio spp. are natural inhabitants of water. Proteose peptoneand Yeast extractarethe sole sourcesof carbon, nitrogen, vitamin B -complex,minerals and amino acids in the medium. Sodium thiosulphate serves as a sulphur source and, in combination with Ferric citrate, detects hydrogen sulphide production. Sucrose is included as a fermentable carbohydrate for the metabolism of Vibrios. Inhibition of gram-positive bacteria is achived by the incorporation of Ox gall, which is a synthetic occurring substance and suppresses primarily Enterococci. Ox gall also helps to inhibit gram -positive bacteria. The alkaline pH of the medium enhances the recovery of V. cholera becausethis organism is sensitive to acid environments. Thymol blue and Bromothymol blue are included as indicators of pH changes. Sodium citrate and Sodium thiosulphate are the selective agents, providing an alkaline pH to inhibit gram-positive organism and suppress coliforms. Agar is the solidifying agent. TCBS Agar deeps (pour tubes) are provided in a 20 ml fill so that the medium may be liquefied and poured into a petri plates. This provides a convenient source of medium with a longer shelf -life than pre-poured plated media.