Longwave or Ultraviolet A (UVA) lamps emit UV light from 315 to 400nm. UVA lamps are used for bacterial identification, staining, electrophoresis, pesticide analysis, fluorescence photography, visualizing nucleic acids, and other genetic work. UVA is also useful for monitoring chlorination, in fluorochemistry, titrations, thin-layer chromatography (TLC), food contamination identification, water testing, and forensic applications.

Medium-wave or Ultraviolet B (UVB) lamps emit light in wavelengths from 280 to 315nm and are used for gel electrophoresis, viewing, and other procedures. UVB light is also used in transilluminators, which are devices used in molecular biology applications to visualize DNA or RNA electrophoretic separation in an agarose gel. Gels are stained with fluorescent dyes that bind to the nucleic acids to make them visible under UVB light. This technique helps researchers size PCR products, quantify DNA, and verify the integrity of extracted RNA.

Shortwave or Ultraviolet C (UVC) lamps emit light in the 100 to 280nm range. Often used as germicidal lamps, UVC is commonly used to disinfect surfaces in laboratories and food-processing facilities and to disinfect water. UVC lamps are also used to cure polymers and for fluorescent analysis, in fluorochemistry, pesticide analysis, DNA and other biochemical testing, microbiological testing, electrophoresis, and photochemistry.

Use caution when using UV lamps. Place them in separate or low-traffic areas to help reduce exposure.

• Enclose UV lamps inside light-tight cabinets or enclosures wherever possible and use screens, shields, and barriers to otherwise contain the UV radiation
• Always use transilluminator covers and replace them immediately if they are discolored, degraded, or damaged
• Do not override any locking devices that help prevent accidental exposure