The PROTEOSTAT® Detection Reagent in all these references (ENZ-51023, ENZ-51035 and ENZ-51027) is light sensitive. Avoid direct exposure of the reagent to intense light. Aliquot and store unused reagent at -20°C, protected from light. Avoid repeated freeze/thaw cycles. To avoid photo-bleaching, perform all manipulations in low light environments, in amber microcentrifuge tubes or protected from light by other means.