Presumptive screening test for seminal acid phosphatase using sodium thymolphthalein monophosphate

The use of sodium thymolphthalein monophosphate for presumptive seminal acid phosphatase testing is discussed. Recent evidence reveals that the dye (o-dianisidine) used in conjunction with alpha-naphthyl phosphate for seminal acid phosphatase testing is a carcinogenic hazard. Numerous tests for seminal acid phosphatase were conducted with swabs from sexual assault kits to compare both substrates. Results of tests using sodium thymolphthalein or alpha-naphthyl phosphate correlated exactly. Sodium thymolphthalein is an effective alternative for preliminary seminal fluid analysis because of its high degree of selectivity and stability, and because it eliminates the potential health hazard.