TY - JOUR A1 - Hahn, Marc Benjamin A1 - Meyer, Susann A1 - Kunte, Hans-Jörg A1 - Solomun, Tihomir A1 - Sturm, Heinz T1 - Measurements and simulations of microscopic damage to DNA in water by 30 keV electrons: A general approach applicable to other radiation sources and biological targets T2 - Physical Review E N2 - The determination of the microscopic dose-damage relationship for DNA in an aqueous environment is of a fundamental interest for dosimetry and applications in radiation therapy and protection. We combine geant4 particle-scattering simulations in water with calculations concerning the movement of biomolecules to obtain the energy deposit in the biologically relevant nanoscopic volume. We juxtaposition these results to the experimentally determined damage to obtain the dose-damage relationship at a molecular level. This approach is tested for an experimentally challenging system concerning the direct irradiation of plasmid DNA (pUC19) in water with electrons as primary particles. Here a microscopic target model for the plasmid DNA based on the relation of lineal energy and radiation quality is used to calculate the effective target volume. It was found that on average fewer than two ionizations within a 7.5-nm radius around the sugar-phosphate backbone are sufficient to cause a single strand break, with a corresponding median lethal energy deposit being E1/2=6±4 eV. The presented method is applicable for ionizing radiation (e.g., γ rays, x rays, and electrons) and a variety of targets, such as DNA, proteins, or cells. PB - American Physical Society CY - USA KW - DNA KW - Radiation damage KW - Dosimetry KW - DNA radiation damage KW - Single-strand break (SSB) KW - Double-strand break (DSB) KW - Low energy electrons KW - Monte Carlo simulation KW - Radiation damage to biomolecules KW - Plasmid DNA in water KW - Lethal dose KW - Solutions (pH, salinity, cosolutes) KW - Geant4 KW - Microdosimetry PY - 2017 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/40424 AN - OPUS4-40424 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-404244 SN - 2470-0045 SN - 2470-0053 VL - 95 IS - 5 SP - 052419-1 EP - 052419-8 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany