Use of different chemical methods for acid phosphatase in cases of rape.

Generally acid phosphatase (ACP) assay is used for testing cases of alleged rape. Comparison of three different chemical methods for Acid Phosphatase (Andersch's method with p-nitrophenyl-phosphate substrate and tartrate inhibitor (A-Tart), Roy's method with thymolphthalein phosphate substrate (R-TMP), and Babson's method with alphanaphthyl phosphate substrate) indicated that Roy's method (R-TMP) should be the preferred one. This method had both acceptable sensitivity and confirmed specificity. Our data confirmed that the vaginal wash of normal healthy women has a very low level of ACP activity. Because of inconclusive data in the literature regarding this ACP level, a normal and equivocal range of ACP was suggested until more is known about causes and interferences. Possible sources of normal ACP activity in the wash fluids were also indicated.