EC Medium, otherwise known as EC Broth, is a liquid medium used to detect the presence of coliform bacteria in drinking water, wastewater, and foods. Developed by Hajna and Perryl, it was designed to detect coliform bacteria, specificallyE. coli. A buffered Lactose broth, it contains Bile Salts to inhibit Gram-positive bacteria and spore-forming microorganisms while enhancing that ofE.coli. Coliforms can be detected by growth at 37°C, whileEscherichiacoliare detected by growth at 44.5°C. Dipotassium Phosphate and Monopotassium Phosphate act as buffering agents while Sodium Chloride maintains the osmotic balance of the medium. The addition of 4-methylumbelliferyl-β-D-glucuronide (MUG) allows for the rapid detection ofE.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.