Resonant formation of DNA strand breaks by low-energy (3 to 20 eV) electrons

Science. 2000 Mar 3;287(5458):1658-60. doi: 10.1126/science.287.5458.1658.


Most of the energy deposited in cells by ionizing radiation is channeled into the production of abundant free secondary electrons with ballistic energies between 1 and 20 electron volts. Here it is shown that reactions of such electrons, even at energies well below ionization thresholds, induce substantial yields of single- and double-strand breaks in DNA, which are caused by rapid decays of transient molecular resonances localized on the DNA's basic components. This finding presents a fundamental challenge to the traditional notion that genotoxic damage by secondary electrons can only occur at energies above the onset of ionization, or upon solvation when they become a slowly reacting chemical species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chemical Phenomena
  • Chemistry, Physical
  • DNA / chemistry
  • DNA / radiation effects*
  • DNA Damage*
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / radiation effects*
  • DNA, Superhelical / chemistry
  • DNA, Superhelical / radiation effects
  • Electrons*
  • Escherichia coli / genetics
  • Nucleic Acid Conformation
  • Photons
  • Plasmids
  • Quantum Theory
  • Radiation Dosage
  • Radiation, Ionizing


  • DNA, Bacterial
  • DNA, Superhelical
  • DNA