An additional use for optimized psoralens is for the inactivation of pathogens in blood products. The synthetic amino-psoralen, amotosalen HCl, has been developed for the inactivation of infectious pathogens (bacteria, viruses, protozoa) in platelet and plasma blood components prepared for transfusion support of patients. Prior to clinical use, amotosalen-treated platelets have been tested and found to be non-carcinogenic when using the established p53 knockout mouse model. The technology is currently in routine use in certain European blood centers and has been recently approved in the US.