SFM studies of carbon ion induced damages in plasmid DNA

Abstract

In this study we present for the first time detailed scanning force microscopy (SFM) investigations of carbon ion induced damages in plasmid DNA in order to obtain information about the biological effectiveness of particle radiation. For this purpose, we have combined SFM and gel electrophoresis measurements in a dose range between D = 0 Gy and 5000 Gy. After irradiation with C ions, the percentage of double-strand breaks (DSBs) increases drastically, i.e. from initially 0% for D = 0 Gy to 38% for D = 5000 Gy. Increasing the dose over the total range is accompanied by a shortening of the average fragment length from L = 1100 nm to L = 575 nm. In addition to our experiments, the average numbers of induced DSBs per irradiated plasmid and per broken plasmid have been calculated from the SFM measurements. The most important among the numerous results is that a significant amount of plasmids has suffered more than two DSBs for all applied doses, indicating multiple DSBs. The number of DSBs per broken plasmid increases from approximately 1.7 after irradiation with a dose of D = 250 Gy to 3.2 after exposure to the highest dose of D = 5000 Gy. The results provide experimental data for the spatially correlated production of DSBs after carbon irradiation, that are relevant to the understanding of its biological effectiveness.

DNA studies using atomic force microscopy: capabilities for measurement of short DNA fragments

“…Other investigators have subsequently applied AFM for further studies of radiation induced DNA damage (Murakami et al, 2000 ; Brons et al, 2004 ; Psonka et al, 2005 ; Brezeanu et al, 2007 ; Elsässer et al, 2008 ; Ke et al, 2008 ; Gudowska-Nowak et al, 2009 ; Lee et al, 2009 ; González et al, 2012 ). Of particular relevance to measurement of short DNA fragments by high-LET radiations, Psonka-Antonczyk et al ( 2009 ) investigated DNA breakage by Ni ions and observed a reduced average DNA fragment length after 340-Gy irradiation when compared to X-ray irradiations.…”

Fifteen years of Servitude et Grandeur to the application of a biophysical technique in medicine: The tale of AFMBioMed

“…This issue and the subsequent ones were edited by us (except those written by our own laboratory that were handled by Heinrich Hörber, a new editor of JMR following the addition of the keyword AFM to the journal's topic list). The first special issue contained three reviews and 14 research articles …”

“…The first special issue contained three reviews 5-7 and 14 research articles. [8][9][10][11][12][13][14][15][16][17][18][19][20][21] The…”

Scanning force microscopy studies of X-ray-induced double-strand breaks in plasmid DNA

“…target for biological effects of ionising radiation, investigation of DNA damage has attracted much attention in recent years [1][2][3][4][5][6][7][8][9]. After irradiation, much serious damage, such as singlestrand breaks, double-strand breaks or base damage can occur in a DNA molecule.…”

“…Nucleic acids and especially DNA have been extensively investigated with SFM [5][6][7][8][9][19][20][21][22][23], since its invention by Binning and collaborators in 1986 [24]. So far, SFM studies of DNA focused in particular on visualising the DNA structure [19,25,26], manipulating DNA on surfaces [27,28] or using it as a conductive material for future molecular electronics [29][30][31].…”