Qualitative and quantitative determinations of acid phosphatase activity in vaginal washings

In the absence of spermatozoa, acid phosphatase activity (ACP) is an indicator of seminal fluid in cases of sexual assault. Both qualitative and quantitative ACP methods are employed by medical examiners. A large series of cases in which a qualitative test was employed is reported. A method for obtaining and handling specimens by vaginal washing was developed. This method provides suitable specimens for the examination for spermatozoa and the determination of ACP. Specimens obtained from 41 women provided examples of endogenous vaginal ACP and intravaginal seminal ACP. These specimens were used to evaluate qualitative and quantitative ACP methods for the detection of seminal ACP. Tartrate inhibition was not useful for separating endogenous vaginal and seminal ACP activities. The advantages of the method developed for specimen acquisition and of quantitative assays for ACP are discussed.