ATP testing is used for measuring the growing microorganisms by using adenosine triphosphate, or ATP for their detection.
ATP is an energy molecule found in living cells, which gives a direct measure of their health and biological concentration. ATP can be quantified by using a luminometer for measuring the light produced through its reaction with the enzyme luciferase.
ATP tests are useful for:
- Guide biocide dosing programs
- Determine corrosion and deposit process type
- Measure equipment or product sanitation
- Manage fermentation processes
- Determine drinking water cleanliness
- Assess soil activity
- Control biological treatment reactors
The first generation ATP tests were derived from hygiene monitoring applications and therefore the samples were relatively free of interferences. The second generation tests are designed specifically for industrial applications, wastewater, and water. In the second generation ATP tests the samples contain, for the most part, a variety of interfering components.
There are two types of ATP within a water sample containing microorganisms:
- Extracellular ATP, which is located outside of biological cells. The extracellular ATP has been released from stressed or dead organisms.
- Intracellular ATP, which is contained inside the living biological cells.
It is important to perform accurate measurements of these two types of ATP in order to assess biological health and to control water and wastewater processes.
ATP bioluminescence tests have moved mainstream. They are also used in the food industry in order to keep food manufacturing clean. The tests are a reliable, simple, and rapid way to monitor surface contamination in the food industry and to detect contaminants in beverages or drinking water. For surface contamination testing it is used a pen like device which is swabbed over the tested area, then inserted into the handheld reader called relative light unit or RLU, on short. The results are displayed within seconds and can indicate if the sample is clean or unclean. The tests are cheap, as they cost only a few dollars per test. The ATP methods only give a broad indication of the presence of organic substances and not specific microorganisms containing ATP. For this reason they need to be used together with microbial culture tests in order to indicate the type of microorganisms present in the sample.
Using surface ATP bioluminescence testing in the food industry is a proactive tool to assure the processing equipment is clean. It is estimated that 80 percent of the food production facilities in North America and more that 80 percent in Europe are using this ATP testing technology for sanitation monitoring and validation of whether the processing equipment is clean enough to be used for food production.
The widespread adoption of ATP testing resulted from a few important advances in the technology. The instrumentation increased in performance and utility and decreased in size and price. The chemistry improved to the current use of synthetic enzyme that is more temperature tolerant and robust. The ATP testing technology is much easier to use today than it was twenty years ago. The handheld testing devices have a weight of just about a pound. The modern ATP testing devices also include software and in many cases they can be linked to databases in order to help the production managers in the decision making process. It is estimated that the ATP testing will soon spread on new markets such as fast food, hospitals and health services.