Used as a selective culture medium for the isolation of enteric pathogens, particularly Salmonella and Shigella species, from clinical and non-clinical samples. The agar inhibits the growth of Gram-positive bacteria and normal intestinal flora through the action of bile salts and citrate, allowing selective growth of target organisms. Colonies of Salmonella typically appear as transparent or translucent with a black center due to hydrogen sulfide production, while Shigella forms pink to colorless colonies depending on lactose fermentation. Commonly used in food testing, water analysis, and stool sample examination in diagnostic laboratories.