Used in microbiology laboratories to test the ability of microorganisms to utilize acetamide as the sole source of carbon and energy. It is a differential medium particularly for identifying Gram-negative bacteria, such as non-fermenters like Pseudomonas aeruginosa (positive) and Enterobacteriaceae like Escherichia coli (typically negative). Growth in the medium indicates acetamidase activity, producing ammonia and causing a pH increase, often detected with a pH indicator. Commonly applied in clinical microbiology for bacterial identification, as well as in quality control for water and food.