A comparative study on low-energy ion beam bombardment
with neutralized beam bombardment of DNA was carried out to
check ion charge effect on inducing DNA damage and subsequent
mutation of DNA transferred bacteria. It was found from our statistically
analyzed results on ion beam and neutralized beam bombardments
of plasmid DNA pGFP that the ion charge played a
certain role in inducing DNA conformation change and consequent
mutation. Generally, charged ion beam bombardment of DNA
could induce mutation in high probability compared with neutralized
beam bombardment though both irradiations resulted in similar
DNA conformation changes. The intrinsic reason was attributed
to additional DNA deformation and contortion caused by ion
charge exchange effect so that the ion beam induced DNA damage
could hardly be completely repaired, whereas the neutralized
beam induced DNA damage could be more easily recoverable owing
to absence of the additional DNA deformation and contortion.