DNA Damage by OH Radicals Produced Using Intense, Ultrashort, Long Wavelength Laser Pulses

• DOI: 10.1103/physrevlett.112.138105
• Publication Date: 2014-04-02T23:20:52Z
• Authors: A. K. Dharmadhikari; H. Bharambe; J. A. Dharmadhikari; J. S. D’Souza; D. Mathur
• Keywords: Hydroxyl Radical; Lasers; 0103 physical sciences; Thermodynamics; DNA Breaks, Double-Stranded; DNA; DNA Breaks, Single-Stranded; 01 natural sciences

We probe femtosecond laser induced damage to aqueous DNA, relying on strong-field interaction with water wherein electrons and free radicals are generated in situ; these, turn, interact DNA plasmids under physiological conditions, producing nicks. Exposure intense pulses of 1350 2200 nm light induces single strand breaks double (DSBs) DNA. At the longer wavelength (and at higher intensities), rotationally hot OH induce DSBs, linear Strand occur due or multiple hits With light, DSBs formed mostly by action two radicals; use scavengers establishes that probability a two-hit event reduces much faster than one-hit as scavenger concentration is increased. Thermal effects do not light.