Pros and Cons of ATP vs. Bacterial Counts – The Need for Complementary Measurement Strategies

In healthcare environments, ATP is good in that it’s quick but bad in that it’s not a great indicator of microbial risk (counts both live and dead bacteria, doesn’t differentiate pathogens from non-pathogens).  Counting of bacterial colony forming units (CFUs) is good in that it’s a great indicator of microbial risk (counts only viable organisms, and selective agars can differentiate pathogens/indicators from non-pathogens easily) but bad in that it takes at least a day while you wait for colonies to grow, and then you’re stuck with contaminated and potentially hazardous agar plates to dispose of.


Using these methods in a complementary fashion makes sense – ATP as a general barometer of cleaning and hygiene, and Bacterial Counts for checking for levels of specific microbes.

Benjamin Tanner holds a B.S. in Molecular Biology and a Ph.D. in Microbiology and Immunology from the University of Arizona, where he studied environmentally mediated disease transmission and assessed infection risks for workers. Dr. Tanner is the founder and principal of Antimicrobial Test Laboratories, LLC, a microbiology laboratory that specializes in testing and development of disinfectant chemicals and other antimicrobial technologies.