Used as a selective enrichment medium for the detection and recovery of coliform bacteria and E. coli in water, food, and environmental samples. Supports the growth of gram-negative enteric bacteria while inhibiting gram-positive organisms due to the presence of bile salts or other selective agents. Commonly used in the first step of the most probable number (MPN) method to estimate microbial density. After incubation, gas production from lactose fermentation indicates the presence of coliforms, guiding further testing like EC broth or membrane filtration for confirmation.