Radioimmunoassay detection limits for 19-OH F1 alpha/F2 alpha prostaglandin in normal, infertile and vasectomized semen stains. Analysis of saliva, sweat and urine for possible non-specific or matrix effects

The sensitivity of a simple radioimmunoassay (RIA) for the detection of 19-OH prostaglandin F1 alpha/F2 alpha (PG F) has been evaluated on a number of semen samples from vasectomized, infertile and fertile donors. The specificity of the test has been examined by testing saliva, sweat and urine from a number of male and female donors. The assay technique could readily detect the PG in semen stains prepared from 0.2 microliter of semen from normal, infertile and vasectomized donors. The detection limit of the assay system, based on the observed displacement, was calculated to be approximately 0.05 microliter semen. The assay could be conducted over a pH range of 7.5-10.5 even after the PG has been heated to 100 degrees C. The 19-OH series of PG were absent from sweat, saliva and female urine using the normal assay protocol; volumes in excess of 100 microliters of some urines particularly from women in labour and those with acute urinary tract infection showed some displacement. Low levels of PG were detected in 50% of the male urine analysed. However, urine samples from men who had engaged in recent sexual activity contained relatively high concentrations of PG which could be readily detected in 10 microliters of urine. These results emphasise the potential of these compounds as specific and sensitive markers for the presence of human semen.