Effects of nonoxinol-9 on the ability to obtain DNA profiles from postcoital vaginal swabs.

Nonoxinol-9, the active ingredient of many spermicide foams and creams, has been shown to inactivate effectively high titres of HIV in vitro. Therefore the early administration of nonoxinol-9, perhaps by a rape victim herself, has been suggested as a potential prophylactic therapy for prevention of a possible HIV infection. For forensic DNA identity testing, it becomes pertinent to determine whether nonoxinol-9 could have an adverse effect on the recovery of high molecular weight DNA from postcoital vaginal swabs and thereby have an impact on restriction fragment length polymorphism (RFLP) analysis. If high molecular weight DNA can not be recovered, it may still be possible to proceed with analyses using PCR-based tests. In order to investigate the potential effects of nonoxinol-9, inserts, gels, or sponges containing nonoxinol-9 were applied either 15 min pre- or 15 to 60 min post coitus. Postcoital vaginal swabs were taken one and six h after sexual intercourse, the DNA was isolated and DNA identity typing was performed. The results demonstrate that nonoxinol-9 has no negative effect on the ability to obtain DNA profiles, either RFLP or PCR-based, from postcoital vaginal swabs. The quantity of extractable high molecular weight DNA obtained (as determined by slot-blot analysis) was comparable with that from uncontaminated postcoital vaginal swabs. RFLP patterns and PCR-based typing results at the HLA-DQ alpha and D1S80 loci from the nonoxinol-9 treated swabs were consistent with the uncontaminated control swabs and the corresponding whole blood samples of the donors. Therefore an early prophylactic administration of the topical anti-HIV agent nonoxinol-9 is not an impedient for obtaining DNA profiles from evidentiary material.