For selective isolation of Vibrio cholerae & other enteropathogenic Vibrios causing food poisoning. TCBS AGAR (VIBRIO SELECTIVE AGAR) is highly selective for the isolation of Vibrio choleraeand V.parahaemolyticusfrom stool specimens, and specified in standard methods for food testing. This highly selective medium meets the nutritional requirements ofVibriospeciesand allows competing with intestinal flora. Vibriospeciesis able to grow in media containing increased salt concentrations. Vibrio speciesare natural inhabitants of water. Proteose peptoneand Yeast extract are the sole sources of 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 Vibrio. Inhibition of gram-positive bacteria is achived by the incorporation of Ox bile, which is a synthetic occurring substance and suppresses primarily Enterococci. Ox bilealso helps to inhibit gram -positive bacteria. The alkaline pH of the medium enhances the recovery of V. choleraebecause this 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.