Microarray technology for the study of DNA damage by low-energy electrons

The damage induced to a model DNA (dT25) immobilized on a gold surface by the interaction of low-energy (1 eV) electrons was studied by means of microarray technology. High quality single-stranded DNA arrays were hybridized with a dye-marked complementary strand after irradiation with electrons and the normalized fluorescence data were used to quantify the DNA damage. The data clearly show the sensitivity of the method. A significant loss of genetic information was already observed at dose as low as few hundred of electrons per immobilized oligonucleotide. The results imply that single stranded DNA and RNA are appreciably more sensitive to radiation and the attack of secondary electrons during replication, transcription or translation stages than the current radiation damage models envisage. PACS. 34.80.Ht Dissociation and dissociative attachment by electron impact – 34.80.Lx Electron-ion recombination and electron attachment – 87.14.Gg DNA, RNA