Photorepair light exposures are performed on microorganism samples following UV light exposure (i.e. UV disinfection) to determine microorganism regrowth and repair kinetics. Photorepair is a light-dependent, enzyme mediated DNA repair process in bacteria that may reverse UV-induced DNA damage and decrease UV disinfection efficacy. Previously, photorepair kinetics were determined on a time-basis (i.e. exposure times). However, time-based photorepair determinations are not standardized. A photorepair fluence response protocol was developed here according to a standardized protocol proposed by Bohrerova and Linden (2007). If you cite your use of this protocol, you should also cite the relevant original literature.