Nanomechanical fingerprints of UV damage to DNA

Abstract

The nanomechanical fingerprints elasticity of UV-damage to DNA in a dose- and sequence-dependent manner, using Atomic Force Microscopy (AFM)-based single-molecule force spectroscopy, was analyzed. The force spectrograms results indicate a significant differences in the elasticity of UV-treated individual DNA molecules as compared to the untreated DNA. The UV treatment shortens the B-S DNA transition length below 70% of the original contour length measured for the untreated DNA. The elasticity of individual duplexes exposed to various doses of radiations of UV light shows that the shortening of the B-S transition is equivalent to that recorded on UV-irradiated DNA. The results also show that UV radiation affects the mechanics of DNA double helix at a single-molecule level in a dose-dependent manner and the irradiated synthetic DNA shows a damage saturation in a sequence-dependent manner.