Detecting radiation-induced DNA damage: from changes in dielectric properties to programmed cell death

The purpose of this work is to detect sequential processes leading, from the very early events induced from the deposition of energy on the DNA helix structure and associated with the release of Na+ counterions from the DNA macromolecule, to the disruption of the cell membrane, the final stage of the programmed cell death. To follow up the evolution of these sequential events, broadband dielectric relaxation spectroscopy was integrated in a series of techniques comprising, additionally, thermal transition spectroscopy, pulsed field gel elecrophoresis, multiple microgel `comet assayʹ, detection of caspases activation and DNA repair inhibition, and scanning electron microscopy. Using these techniques, the induction of DNA degradation and cell membrane disruption in human peripheral blood mononuclear cells was investigated.