Brilliant Green Bile Broth 2%, also referred to as Brilliant Green Bile Broth or Brilliant Green Bile Lactose Broth, is a liquid medium used for confirming the presence of coliforms in water, sewage, and dairy products. Brilliant Green and Oxbile inhibit Gram-positive and most Gram-negative bacteria. Lactose is the main carbohydrate source. Upon its fermentation by the coli-aerogenes group, rapid formation of gas can be observed.