Bismuth Sulfite Agar, 250g

Bismuth Sulfite Agar is a highly selective medium used for isolating Salmonella spp., particularly Salmonella Typhi, from food and clinical specimens.

Test principle

In Bismuth Sulfite Agar, beef extract and peptone provide nitrogen, vitamins and minerals. Dextrose is an energy source. Disodium phosphate is a buffering agent. Bismuth sulfite indicator and brilliant green are complementary in inhibiting gram-positive bacteria and members of the coliform group, while allowing Salmonella to grow luxuriantly. Ferrous sulfate is included for detection of H2S production. When H2S is present, the iron in the formula is precipitated, giving positive cultures the characteristic brown to black color with metallic sheen. Agar is the solidifying agent.