Also known as ultraviolet light, black light causes various materials to "fluoresce" or radiate visible light in total darkness. Substances such as bacteria, urine, seminal fluid and blood are detected by black light inspection. Flavin (found in Vitamin B) is also a material that emits a fluorescent glow when exposed to UV light. Scientist have discovered that germs tend to congregate on surfaces where high levels of flavin are present. The use of a germ-detecting black light offers a road map to areas in the home where bacteria reside.
Obtain a germ-detecting UV light. Professional-grade UV lights emit UV rays in the long frequencies required for the detection of bacteria. UV light is part of the electromagnetic spectrum and ranges between 100 to 400 nanometers. Professional UV lights emitting wavelengths ranging from 386 to 400 nanometers are suitable for detection of bacteria in the home.
Perform a preliminary cleaning and preparation of the home. Preliminary cleaning and preparation will make it easier to maneuver in the dark. Areas behind and under furniture and appliances are areas of interest, and will need to be accessible during inspection.
Turn of all lights and inspect all surfaces in the home with the black light. The area must be completely dark for the black light to expose bacteria. Start in one corner of the room and sweep from corner to corner, hovering over the surfaces of the room including beds, counter tops, floors and walls. Any bacteria or other contaminate will illuminate under the black light to expose the bacteria within the home.