AquaSnap^® Free is a water ATP test that measures non-microbial ATP (aka dead cells) in a solution.  Use AquaSnap^® Free in combination with AquaSnap^® Total to identify the microbial ATP in a water sample. First, test a sample of water using AquaSnap^® Total and record number (total load). Then, use AquaSnap^® Free on the same sample and record this number (free ATP). The difference between AquaSnap^® Total and AquaSnap^® Free provides an indication of the microbial ATP contamination in the sample. It works hand-in-hand with the EnSURE^® Touch Monitoring System.