The First Definitive Water Test System For Coliforms & E. coli. Not only does ColitagTM detect both total coliforms and E. coli bacteria in water samples - it's the only U.S. patented system that definitively tests for both MUG-positive and MUG-negative E. coli. That means accurate results you can be sure of, without concern for false negative readings. Colitag also automatically resuscitates and then detects chlorine-injured bacteria, giving you a highly sensitive tool for regulated site testing. And Colitag does all this using a simple, ready-to-use medium that you combine with a water sample for results you can count on with complete certainty. Test with confidence. Test with Colitag.