You see, blood does not fluoresce by applying UV or visible blue light.
Although blood does not fluoresce, certain other physiological fluids will.
UV alternate light sources can reveal the following: seminal fluid, saliva and urine stains.
Also, certain narcotics will fluoresce as will bone and teeth fragments.
What shows up under a blacklight?
Vitamins, Fluids and Chlorophyll
Vitamins A and B, niacin, riboflavin and thiamine all shine under black lights. Blood, semen and urine contain florescent molecules, which make them visible under black light. Grinding up plants into a chlorophyll-type paste makes them illuminate a red shade under black light.
What bodily fluids can be seen with a black light?
The same holds for many organic substances, and most bodily fluids—including sweat, saliva, and urine—will shine when you put them under an ultraviolet “black light.” Semen happens to glow the brightest, however, on account of the particular mix of chemicals it contains.
Does female discharge show up under a blacklight?
Semen shows up with a black light, but discharge from a woman’s vagina can may also show up. In the descriptive literature there are varying examples of the color of stains under UV lights, however this is not linked to particular wavelengths or circumstances.
What glows orange under black light?
Black lights earn their name because they give off very little light that can be seen by us. Light in the visible spectrum ranges from red, orange, and yellow, to violet. Tonic water is another household item that glows under UV-A rays of a blacklight. The fluorescent dyes in laundry detergent will also glow.
Photo in the article by “Picryl”