In the detection of E. coli and coliforms. Bile and brilliant green extensively inhibit the growth of accompanying flora, in particular gram-positive microorganisms. The presence of E. coli results in fluorescence in the UV. A positive indole test and possibly gas formation from lactose fermentation provide confirmation. The broth can be used in conjunction with the MPN method for E. coli and coliform enumeration in the water of bathing areas.