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Nanoscale detection of ionizing radiation damage to DNA by atomic force microscopy

Ke, Changhong and Jiang, Yong and Mieczkowski, Piotr A. and Muramoto, Garrett G. and Chute, John P. and Marszalek, Piotr E. (2008) Nanoscale detection of ionizing radiation damage to DNA by atomic force microscopy. SMALL, 4 (2). pp. 288-294.

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The detection and quantification of ionizing radiation damage to DNA at a single-molecule level by atomic force microscopy (AFM) is reported. The DNA damage-detection technique combining supercoiled plasmid relaxation assay with AFM imaging is a direct and quantitative approach to detect gamma-ray-induced single- and double-strand breaks in DNA, and its accuracy and reliability are validated through a comparison with traditional agarose gel electrophoresis. In addition, the dependence of radiation-induced single-strand breaks on plasmid size and concentration at a single-molecule level in a low-dose (1 Gy) and low-concentration range (0.01 ng mu L-1-10 ng mu L-1) is investigated using the AFM-based damage-detection assay. The results clearly show that the number of single-strand breaks per DNA molecule is linearly proportional to the plasmid size and inversely correlated to the DNA concentration. This assay can also efficiently detect DNA damage in highly dilute samples (0.01 ng mu L-1), which is beyond the capability of traditional techniques. AFM imaging can uniquely supplement traditional techniques for sensitive measurements of damage to DNA by ionizing radiation.

Item Type:Article
Uncontrolled Keywords:atomic force microscopy; DNA; gamma radiation; single-molecule studies
Subjects:Analytical Science > Microscopy and probe methods
Biomedical Science > Nanobiotechnology
Biomedical Science > Nanotechnology for human health
ID Code:1488
Deposited By:Farnush Anwar
Deposited On:11 Dec 2008 20:30
Last Modified:11 Dec 2008 20:30

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