RLU stands for Relative Light Unit and is the unit of measure used in bioluminescence. When a test swab is activated, a bioluminescent reaction occurs, generating light output. Luminometers measure and quantify that light as an RLU output. Because manufacturers use different sensor technologies and algorithms for adding up the photons, RLU measurements will vary from system to system. However, because the ATP bioluminescence reaction is linear, the more ATP present means the more light will be present. This makes comparing systems easy. (Comparing RLU values is like comparing Fahrenheit and Celsius; they are two different scales for the same temperature).
The relationship between the amount of ATP in the sample and the RLU result reading on the luminometer is simple:
High contamination (improper cleaning) = Large amount of ATP = More light produced in reaction= High RLU reading on SystemSURE™ Plus, EnSURE™ or EnSURE™ Touch.
The RLU reading is directly proportional to the amount of ATP collected from the sample. A high RLU reading indicates a large amount of ATP at the test location. This in turn indicates improper cleaning and the presence of contaminants.
Cleaning properly results in less ATP at the location. Less ATP results in less light output during the bioluminescent reaction and consequently, a lower RLU reading.