Used in microbiology to isolate and differentiate enteric pathogens, particularly Salmonella and Shigella species, from clinical and non-clinical samples. The medium inhibits the growth of Gram-positive bacteria and most non-pathogenic Enterobacteriaceae through the action of bile salts and desoxycholate. Lactose fermentation is used to distinguish colonies: lactose fermenters like Escherichia coli produce pink colonies due to acid production, while non-fermenters such as Salmonella and Shigella appear colorless or transparent. This selective and differential property makes it valuable in diagnostic laboratories for detecting foodborne and waterborne pathogens in stool samples, food, and environmental specimens.