DNA damage quantitation by alkaline gel electrophoresis.

Quantifying DNA lesions provides a powerful way to assess the level of endogenous damage or the damage level induced by radiation, chemical or other agents, as well as the ability of cells to repair such damages. Quantitative gel electrophoresis of experimental DNAs along with DNA length standards, imaging the resulting dispersed DNA and calculating the population average length allows accurate measurement of lesion frequencies. Number average length analysis provides high sensitivity and does not require any specific distribution of lesions within the DNA molecules. These methods are readily applicable to strand breaks and ultraviolet radiation induced pyrimidine dimers, but can also be used-with appropriate modifications-for ionizing radiation-induced lesions such as oxidized bases and abasic sites.