The MEASURE program out of University of North Carolina and Aquagenx have developed a Compartment Bag Test (CBT) for determining whether water is safe from dangerous bacteria like E coli. Tests have been conducted in Peru, where they have partnered with the Ministry of Health, and across the globe.The CBT is a portable test that requires no other equipment or inputs besides 100 mL of water. The water sample is mixed with the culture medium, then poured into the bag. After overnight incubation, bacterial contamination can be determined based on if the water turns blue. The color change is based on E coli's hydrolysis of a fluorogenic compound that is blue under long UV light.