Dried Semen stains on clothes identified by:
B i.e. UV rays When examined under filtered ultraviolet (UV) light, seminal fluid (semen) show a fluorescence of bluish white colourQ, which is not specific as other albuminous materials such as nasal, leucorrhoeal discharges, detergents and stains of urine also fluoresce.
Spectrometry
UV rays
Infrared rays
LASER