Determination of laser-induced thymine-thymine dimer in DNA by LC

A new simple and selective high-performance liquid chromatography (HPLC) method has been developed for the determination of thymine-thymine (T-T) dimer in deoxyribonucleic acid (DNA) for the study of relationship between the yield of T-T dimer and laser irradiation conditions. The HPLC method is not disturbed by other hydrolysate formed in DNA with the good stability and reproducility. The detection of limit of the method is about 8.8 ng of T-T dimer in DNA blank. Three lever of laser intensity to irradiate DNA were selected for calf thymine to test the influence of the pulse number. The mechanism of DNA lesion and repair caused by laser irradiating was studied.