TCBS (Thiosulfate Citrate Bile Salts Sucrose) Agar medium is used for isolating and cultivatingVibriocholeraeand other enteropathogenic bacteria. TCBS is prepared according to the formula of Kobayashietal. The pH of the medium is elevated to enhance the growth ofV.cholerae. Sucrose is fermented byV.choleraeand its biotypeEltorproducing yellowish-brown flat colonies. Fishbeinetal. reported thatV.parahaemolyticusproduces light blueish colonies. Enteric and Gram-positive bacteria present in fecal specimens, includingProteusspp., are inhibited by the high concentrations of Sodium Thiosulfate and Citrate, the alkaline pH, and the presence of Bile Salts. TCBS Agar was also found useful in the isolation ofV.fluvialisandV.vulnificus. Bromothymol Blue and Thymol Blue are pH indicators. Together with the fermentable sugar Sucrose, they allow to distinguish sucrose-fermenting (yellow colonies) and non-fermenting (green colonies) species.