Electrophoretic separation of nucleic acids: evaluation by video and photographic densitometry.

The separation of DNA by gel electrophoresis provides a rapid method for determining size distributions of DNA in solution. Densitometric scanning of photographs of gels has been the standard method of analysis of agarose gels. However, analysis of photographs is complicated by the non-linear response of photographic film. Charged-coupled device video cameras have become popular for quantitative densitometry and we have used a charge-coupled device camera to image agarose gels to quantitate DNA damage. We compare video and photographic densitometry for quantitation of ultraviolet radiation (UV)-induced DNA damage and find that the two methods give equivalent results.