Hahn, Marc BenjaminMeyer, SusannSchröter, Maria-AstridSeitz, HaraldKunte, Hans-JörgSolomun, TihomirSturm, Heinz2018-04-192018-04-1920161463-9076https://depositonce.tu-berlin.de/handle/11303/7642http://dx.doi.org/10.14279/depositonce-6832We report on a study in which plasmid DNA in water was irradiated with 30 keV electrons generated by a scanning electron microscope and passed through a 100 nm thick Si3N4 membrane. The corresponding Monte Carlo simulations suggest that the kinetic energy spectrum of the electrons throughout the water is dominated by low energy electrons (<100 eV). The DNA radiation damage, single-strand breaks (SSBs) and double-strand breaks (DSBs), was determined by gel electrophoresis. The median lethal dose of D1/2 = 1.7 ± 0.3 Gy was found to be much smaller as compared to partially or fully hydrated DNA irradiated under vacuum conditions. The ratio of the DSBs to SSBs was found to be 1 : 12 as compared to 1 : 88 found for hydrated DNA. Our method enables quantitative measurements of radiation damage to biomolecules (DNA, proteins) in solutions under varying conditions (pH, salinity, co-solutes) for an electron energy range which is difficult to probe by standard methods.en540 Chemie und zugeordnete WissenschaftenArticle1463-9084