Review Of Black Light To Detect Body Fluids References. In forensic investigations, black lights are used to reveal the presence of trace evidence, such as blood, urine, semen and saliva, by causing visible fluorescence in these substances. Web antifreeze, some rocks and minerals, tonic water and even olive oil emit some light under a black light.
This can happen in two broad ways, chemiluminescence and photoluminescence. Web english in this activity, students examine a variety of materials to determine whether they contain phosphors and relate the activity to forensics. The stain will glow in a purple color.
