Shining a light on ATP systems

May 23, 2019

What do fireflies and ATP, or adenosine triphosphate, hygiene monitoring systems have in common?

The science behind the instant detection of organic matter by ATP systems finds its origins in the study of fireflies. In these insects, two chemicals, luciferin and luciferase, react with the molecule ATP, which is found in every living cell, to produce light.

Known as bioluminescence when it is natural, or chemiluminescence when it is part of a manmade product, this reaction is the basis of ATP hygiene monitoring systems.

In ATP hygiene monitoring systems, the light produced by the reaction of ATP is measured by a luminometer. The luminometer contains a device that detects how much light is produced by the chemiluminescent reaction happening in the samplers, either through a photomultiplier or a photo-diode.

The principle of an ATP system is to collect ATP molecules with a sampler or a swab before activating the device by pushing into its cartridge. The ATP is then mixed with the luciferin and the luciferase present in the liquid or reagent pad of the cartridge.

More ATP = more light

As there is a fixed amount of luciferin and luciferase in the liquid or reagent pad, the amount of light produced is directly proportional to the amount of ATP collected by the samplers. The light is then read by the luminometer through a series of readings taking place over several seconds. Readings are then reported in relative light units (RLUs) and results returned as pass, marginal or fail, based on previously established thresholds of RLU levels.

Simply put, the dirtier the surface is, the more ATP is collected on the sampler and the more light is produced by the chemiluminescent reaction.


Category: Food Safety, Food & Beverage, Environmental Monitoring