Investigation of neutron-induced damage in DNA by atomic force microscopy: experimental evidence of clustered DNA lesions.
Using atomic force microscopy (AFM), we have investigated neutron-induced DNA double-strand breaks in plasmids in aqueous solution. AFM permits direct measurement of individual DNA molecules with an accuracy of a few nanometers. Furthermore, the analysis of the DNA fragment size distribution is non-parametric, whereas other methods are dependent on the model. Neutron irradiation of DNA results in the generation of many short fragments, an observation not made for damage induced by low-LET radiation. These data provide clear experimental evidence for the existence of clustered DNA double-strand breaks and demonstrate that short DNA fragments may be produced by such radiations in the absence of a nucleosomal DNA structure.
Pang
D
D
Department of Radiation Medicine, Georgetown University Medical Center, Washington, DC 20007, USA.
Berman
B L
BL
Chasovskikh
S
S
Rodgers
J E
JE
Dritschilo
A
A
D004247:DNA / Q000737:chemistry / Q000528:radiation effects* / Q000648:ultrastructure; D004249:DNA Damage; D066298:In Vitro Techniques; D018625:Microscopy, Atomic Force; D009502:Neutrons / Q000009:adverse effects*; D010957:Plasmids / Q000737:chemistry / Q000528:radiation effects / Q000648:ultrastructure; D012062:Relative Biological Effectiveness; D012996:Solutions; D014867:Water
D012996:Solutions; D014867:Water; D004247:DNA