DNA in female sexual fluids?

Dear Alice,

Is it possible to find female PSA, or other types of sexual fluids on another female? For example, if there was a case of women on women rape, could it be possible to find the woman's DNA on the victim? Like when they find semen on victims?

Dear Reader,

A great question, with a complex answer. Deoxyribonucleic acid (DNA) — which contains our unique genetic material — is found in various bodily fluids, secretions, and cells, such as blood, sweat, vaginal cells, semen, skin cells, saliva, pubic hair, mucus, urine, and feces. If traces of these substances are left on or inside a person who has been sexually assaulted — male or female — it may be possible to collect DNA that would identify the perpetrator. 

The fluids you mention may be useful in identifying a perpetrator, but have limitations. The prostate-specific antigen (PSA) that may be produced by a woman does not contain DNA and may not be secreted during a sexual assault. A female perpetrator may be more likely to leave behind DNA if she is breast feeding or if she ejaculates during the assault. Other sources of left-behind DNA may be more useful, including hair, skin cells, and saliva from the perpetrator. Alhough it may be psychologically difficult to refrain from showering after an assault, DNA collection is more successful if identifying secretions are not washed away.

If you or someone you know has experienced an assault, you can get support from a number of sources. You may be interested in also checking out the question Was I raped? for more information.  In addition to talking to your primary care provider, or a trusted counselor, you may want to visit the Rape, Abuse, and Incest National Network

Thanks again for your question,

Last updated Jul 26, 2015
Originally published Feb 25, 2010