A single-molecule study on the structural damage of ultraviolet radiated DNA.

The structural damage of double-stranded DNA under UV radiation was examined using single-molecule fluorescence microscopy. Compared to undamaged DNA, the diffusion coefficient of lambda-DNA was significantly increased with 12 min or 20 min of radiation but remained unchanged for 40 min of exposure possibly due to strand crosslinking. The structural damage of DNA was further examined using transmission electron microscopy which revealed kinks and sharp bends along the DNA backbone.