A fluorescence-based method for detection of electron damage to DNA

The decomposition of DNA oligonucleotides with the sequences G6T3G6 and G6(BrU)3G6 (BrU = 5-bromouracil) by electrons with energy lower than the electronic excitation energy was studied by a fluorescence method. The single stranded oligonucleotides were immobilized on a gold surface in a microarray format. After the electron irradiation they were hybridized with the complementary C6A3C6 strand marked with a dye. The fluorescence signal in positive and negative tests showed clearly the decomposition of the BrU and T oligonucleotides by low energy electrons.