Real-time testing of endoscope lumens/elevator channel should be done immediately after manual cleaning so that any improperly cleaned devices are re-cleaned prior to High level disinfection.
To confirm the adequacy of manual cleaning, a rapid cleaning monitor (or rapid audit tool) for residual organic soil can be used prior to high-level disinfection. If the tool results are positive, this allows for the recleaning of the endoscope prior to disinfection. The frequency of the testing should be determined by the individual institutions ( 2016 Standards of Infection Prevention in Reprocessing of Flexible Gastrointestinal Endoscopes, p18-19)
AAMI ST 12.4.3 recommends establishing a reasonable benchmark. This is the level of cleaning that can be achieved consistently using specific soil markers relevant to devices used for patients.
Common Markers used include Protein, Carbohydrate, Hemoglobin (blood) and Adenosine triphosphate (ATP) (2015 AAMI ST91, p39)