An ultra-violet (UV) transilluminator is a standard piece of equipment used in life science laboratories for visualization of target DNAs and proteins. Sometimes referred to as a gel light box or lab light box, the UV transilluminator works by emitting high levels of UV radiation through the viewing surface. The key application for a UV transilluminator is for visualization of DNA and protein agarose and polyacrylamide gels after electrophoresis. Gels can be directly placed onto the UV transilluminator; wavelength will vary on your particular application. Some considerations to keep in mind when shopping around for a UV transilluminator include viewing surface size for varying size gels; wavelengths, as some models come in single or dual wavelengths; and the dimensions of the benchtop unit.