Detecting sperm on clothes

By Peter Hadfield in Tokyo. Each of them is sprayed on the suspect underwear in turn. If traces of seminal fluid are present, the second spray turns it bright green. But the method is believed to be similar to the most common test for detecting semen used by forensic scientists in Britain. Called the Acid Phosphatase Test, this also uses two chemicals.

Will this work on dried semen stains? That's what you're looking for is dried stains and once the semen is dried on the material that's exactly where it will remain, locked into the fibers of the garment until the next time the item is laundered in a washing machine. How old can the suspected stain be? Dried semen is a very resilient substance that can live on as testable evidence for years when stored at normal room temperature. However, in the vast majority of cases you'll more than likely be testing items that were probably recently stained anyway.

People may wish to confirm the presence of what they suspect to be semen on items such as bed linen or underwear. Semen testing can be carried out to establish whether the stain is really semen or something else. Several companies market infidelity testing kits which allow you to do the entire testing to detect and confirm the presence of semen.

Since body fluids like semen, saliva, and vaginal fluids are naturally fluorescent, the use of a light source offers a unique method for locating them. A crime scene investigator can narrow down the specific locations of stains for collection instead of testing entire, large pieces of evidence such as a mattress, a carpet, a sheet, an article of clothing, etc. The dried body fluids will actually glow under the light source illumination. Because nearly all body fluids are inherently fluorescent, the more powerful and more tunable your light source, the more evidence you will uncover, a good example being the Mini-CrimeScope Advance. Although the body fluids will fluoresce under an ordinary UV black light, many articles on which you would find them including clothing and sheets will also glow and deter their detection.