The Science of ATP Monitoring
What is ATP?
Adenosine triphosphate (ATP) is a chemical produced in all living cells. Its presence on a surface is an indication of organic contamination. That contamination can come from human contact, bacterial presence or some other form of organic residue. The amount of ATP remaining on a cleaned surface is a direct indication of the effectiveness of a cleaning method.
In your facility, people touch surfaces and, in the process, either add to or pick up the organic residue which can include pathogenic microbes such as Clostridium difficile, MVM, or any number of environmentally transferred organisms. For this reason, measuring ATP levels on high-touch surfaces and equipment has become the standard for at-risk facilities in determining cleanliness levels.
The AccuPoint Sampler
When ATP is collected from a surface and combined with two chemicals contained in Neogen’s AccuPoint Samplers, Luciferin and Luciferase, a chemiluminescent reaction occurs. This reaction produces light in the same way that fireflies do. The amount of light produced in the reaction is directly proportional to the amount of ATP collected from the surface. Luciferin / Luciferase + ATP = Light. This light is then measured by the AccuPoint luminometer and reported as relative light units (RLUs).
ATP results do not correlate with microbial counts
It is a common misconception that results received from ATP testing systems in RLU should correlate with a microbial total plate count result for the same sample. There are several reasons why this may not be true.
The amount of ATP in microbial cells can vary dramatically and a single CFU (colony-forming unit) can be composed of one or more cells. Microbes also need food to grow and will seldom be present on a surface alone. They will most often exist within a pool of organic material comprised of many cells all of which may contain ATP. Since there is no way of differentiating the ATP from a pathogenic organism like C. diff and the skin cells that have been shed from a visitor’s fingers, RLU scores may consist of a small amount of bacterial ATP one day and a large amount the next.
So why use an ATP monitoring system?
While ATP systems are not direct indicators of bacterial presence, they are the fastest and most convenient method for determining the potential for these organisms to exist on patient contact surfaces and equipment. There is no faster or easier way to know that you could have a problem or that certain areas require a more rigorous cleaning than to use a system that allows you to correct issues before they become serious problems. Properly utilized sanitation monitoring systems allow for the quick and easy detection and measurement of ATP on high-touch surfaces and equipment which provides an objective, actionable tool for the monitoring of a facility’s sanitation efforts.