Mechanism of High Power Picosecond Laser Uv Inactivation of Viruses and Bacterial Plasmids

The mechanism of inactivating action of high‐power picosecond laser UV radiation (λ= 266 nm) on the λ and φX174 bacteriophages and the pBR 322 plasmid has been studied. It has been shown that at UV radiation intensities from 1011 to 1013 W/m2, inactivation of viruses and bacterial plasmids occurs mainly on account of single‐strand breaks in the DNA chain unlike the case of less powerful UV radiation where the inactivation is associated with the formation of pyrimidine dimers.