Detection of Seminal Material on Hand-Washed Textile Evidence

Background. In sexual assault cases, a medical examination of the victim is often not conducted timely. This leaves the only chance to spot the ejaculate of the assailant on the victim’s clothing. Washing the victim’s clothes before the detection of semen in the forensic laboratory is a challenging task. Therefore, the current study aimed to examine the persistence of seminal material on seven different types of hand-washed fabrics using five laundry detergents. Methods. The presence of seminal material on washed fabrics was determined using an alternate light source, acid phosphatase test, p30 test, and sperm head count. Results. The study demonstrated that presumptive testing was not positive for most washed fabrics. A fairly large number of spermatozoa retained on a few fabrics even after 20 minutes of washing. The cotton yarn fabrics and tight weaving with warf and weft more than 100x100/inch could retain more sperms. The DNA was also isolated from sample and quantified using a Quantifiler Duo DNA quantification kit. Conclusion. Good quality and quantity of human DNA were obtained from most of the washed fabrics, which could successfully generate the STR profile of the donor. The current study recommended using hand-washed textile items for forensic analysis in sexual assault cases.