Penile glycogenated epithelial cells as an indicator of recent vaginal intercourse

Occasionally, suspected male rape assailants are examined, in part to recover evidence of recent sexual intercourse. Glycogenated squamous epithelial cells are felt to be specific for the vagina, and if recovered from the penis, they are indicative of penile vaginal penetration. From the 45 periodic acid-Schiff (PAS) stained postcoital penile smears examined, 36 (81%) contained PAS-positive cells. Precoital penile smears were all negative. Both precoital and postcoital urethral meatus smears contained many PAS-positive cells. The authors conclude that recovery of PAS-positive cells from the penile shaft is strong presumptive, but not definitive, evidence of recent vaginal intercourse.