Merck, B3301-500G, Bile salts

General description
Bile salt is an organic sodium salt with a conjugate of any of the bile acids along with either glycine or taurine. Bile salts are composed of four different kinds of bile acids - cholic, deoxycholic, chenodeoxycholic, and lithocholic acids. Bile salts are extracted under controlled conditions from purified fresh bile, to be used in bacteriological culture media, where it behaves as a selective inhibitory agent that enables isolation and identification of pathogens.
Application
Bile Salts are used in MacConkey Agar and Broth as well as in Fluid Tetrathionate Medium to selectively inhibit bacteria that do not grow in an enteric environment. It is used as a selective agent in culture media for the selective growth of intestinal bacteria like E. coli, other fecal coliforms, and fecal Streptococci. But it is also used as a selective agent in media for the detection of Yersinia enterocolitica, Aeromonas hydrophila, and Vibrio species.
Preparation Note
Extracted from purified, fresh bile.