DNA Testing Can Prove Infidelity
Many divorces in the U.S. are the direct results of sexual infidelity by one or both people in a relationship. The frequency of marital infidelity vary widely, but experts estimates that some 60 percent of husbands and nearly 40 percent of wives have been unfaithful at some point during their marriage. No one sex has a monopoly on infidelity!
Although stains on female undergarments could be attributable to urine, urinary tract infection, blood, feces or natural vaginal excretions related to menstrual cycle, ovulation, or vaginal infection; some stains on female undergarments could possibly indicate sexual infidelity. Semen can be deposited on undergarments, panties, bed sheets, clothing upholstered furniture or other surfaces. For up to 5 days after the sexual act, sperm cells can live in the vagina. Whether on male undergarment or female undergarment, forensic analysis of suspicious stains would be necessary to determine the origin of suspicious stains.
A Forensic lab would need to analyze any suspicious stains in two stages: screening and DNA analysis. A Forensic Analyst screens the suspicious stain using a battery of techniques to determine whether there is semen present. If no evidence of semen is present, on undergarments, or sample presented, then there is no physical evidence of infidelity and, therefore, continued testing is unnecessary.
If the stain is identified as semen, then DNA analysis of the stain and a reference swab sample from the partner, male or female, is conducted to determine whether the semen came from the partner or some other unknown person. Stains that are the results of sexual activity are often a mixture of both partners doing the act, male and female DNA or male and male DNA. Epithelial cells from the vaginal wall, mouth or skin comprises the female DNA. Suspicious stains are cell typed using differential extraction which takes advantage of each cell’s unique type. DNA profiles are generated from each extracted stain as well as from the reference sample for the male and / or female. If the profile from the partner’s sample does not match the DNA from the stain samples presented, then some other man or woman created the stains
Likewise, stains on male undergarments could be an indicator of sexual infidelity with either male or female. As well staining on male undergarments may be caused by urine, urinary tract infection, feces or semen. The same type of analyses would need to be done with the known partner’s reference swab to determine whether the partner caused the tested stains.
Garments and or other samples should be stored at room temperature, and sent to the lab in paper bags or envelopes. Never use plastic bags nor should you refrigerate the sample item. The partner’s reference should be collected from the cheeks of the mouth using sterile swabs and sent to the lab in its own paper container.









