Comparison of various ultraviolet sources for fluorescent detection of ethidium bromide-DNA complexes in polyacrylamide gels.

Ultraviolet sources with output wavelengths or 254, 300, and 366 nm were compared for detection of ethidium bromide-DNA complexes in acrylamide gels. The 254and 300-nni sources were both much more sensitive than the 366-nni source. The 254-nni .source produced a great deal of photodamage, photonickingand photodimerization, and photobleaching, while the longer wavelength sources cause little damage orbleaching. The 300-nm source is clearly the most suitable source, providing high sensitivity and a relatively low amount of photodamage and photobleaching.