Nutrient Agar is used for cultivating a wide variety of non-fastidious organisms. Pancreatic Digest of Gelatin and Beef Extract provide amino acids, peptides, carbohydrates, vitamins, and electrolytes for bacterial growth. 4-methylumbelliferyl-β-D-glucuronide (MUG) allows for the rapid detection of E. coli. MUG is used as a substrate to detect glucuronidase activity, since its degradation by this enzyme produces the fluorescent compound 4-methylumbelliferone, visible under UV light. Agar is the gelifying agent.