G. W. Barendsen, Mechanisms of cell reproductive death and shapes of radiation dose-survival curves of mammalian cells, Int. J. Radiat. Biol, vol.57, pp.885-896, 1990.

G. Binnig, C. F. Quate, and C. Gerber, Atomic force microscope, Phys. Rev. Lett, vol.56, pp.930-933, 1986.

G. Binning, H. Rohrer, and C. Gerber, The scanning tunneling microscope, Sci. Am, vol.253, pp.50-56, 1986.

D. Blöcher, In CHEF electrophoresis a linear induction of dsb corresponds to a nonlinear fraction of extracted DNA with dose, Int. J. Radiat. Biol, vol.57, pp.7-12, 1990.

M. O. Bradley and K. W. Kohn, X-ray induced DNA double strand break production and repair in mammalian cells as measured by neutral filter elution, Nucleic Acids Res, vol.7, pp.793-804, 1979.

R. M. Bremnes, R. Sirera, and C. Camps, Circulating tumour-derived DNA and RNA markers in blood: a tool for early detection, diagnostics, and follow-up?, Lung Cancer, vol.49, pp.1-12, 2005.

S. E. Bresler, L. A. Noskin, and A. V. Suslov, Induction by gamma irradiation of double-strand breaks of Escherichia coli chromosomes and their role in cell lethality, Biophys. J, vol.45, pp.84218-84224, 1984.

M. Brezeanu, G. Taucher-scholz, K. Psonka, F. Träger, and F. Hubenthal, SFM studies of carbon ion induced damages in plasmid DNA, J. Mol. Recognit, vol.20, pp.502-507, 2007.

S. Brons, K. Psonka, M. Heiss, E. Gudowska-nowak, G. Taucher-scholz et al., Direct visualisation of heavy ion induced DNA fragmentation using atomic force microscopy, Radiother. Oncol, vol.73, pp.112-114, 2004.

A. Cerreta, D. Vobornik, G. Di-santo, S. Tobenas, L. Alonso-sarduy et al., FM-AFM constant height imaging and force curves: high resolution study of DNA-tip interactions, J. Mol. Recognit, vol.25, pp.486-493, 2012.

F. K. Chun, I. Müller, I. Lange, M. G. Friedrich, A. Erbersdobler et al., Circulating tumour-associated plasma DNA represents an independent and informative predictor of prostate cancer, BJU Int, vol.98, pp.544-548, 2006.

F. Diehl, K. Schmidt, M. A. Choti, K. Romans, S. Goodman et al., Circulating mutant DNA to assess tumor dynamics, Nat. Med, vol.14, pp.985-990, 2008.

J. Dolezel, J. Barto?, H. Voglmayr, and J. Greilhuber, Nuclear DNA content and genome size of trout and human, Cytometry A, vol.51, pp.127-128, 2003.

M. E. Drew, A. Chworos, E. Oroudjev, H. Hansma, Y. et al., A tripod molecular tip for single molecule ligand-receptor force spectroscopy by AFM, Langmuir, vol.26, pp.7117-7125, 2010.

T. Elsässer, S. Brons, K. Psonka, M. Scholz, E. Gudowska-nowak et al., Biophysical modeling of fragment length distributions of DNA plasmids after X and heavy-ion irradiation analyzed by atomic force microscopy, Radiat. Res, vol.169, pp.649-659, 2008.

C. Esnault, B. Chnais, N. Casse, N. Delorme, G. Louarn et al., Electrochemically modified carbon and chromium surfaces for AFM imaging of double-strand DNA interaction with transposase protein, Chem. Phys. Chem, vol.14, pp.338-345, 2013.
URL : https://hal.archives-ouvertes.fr/hal-00968809

M. Frankenberg-schwager and D. Frankenberg, DNA double-strand breaks: their repair and relationship to cell killing in yeast, Int. J. Radiat. Biol, vol.58, pp.569-575, 1990.

L. N. González, J. D. Arruda-neto, M. A. Cotta, H. Carrer, F. Garcia et al., DNA fragmentation by gamma radiation and electron beams using atomic force microscopy, J. Biol. Phys, vol.38, pp.531-542, 2012.

F. O. Goodman and N. Garcia, Roles of the attractive and repulsive forces in atomic-force microscopy, Phys. Rev. B Condens. Matter, vol.43, pp.4728-4731, 1991.

E. Gormally, P. Hainaut, E. Caboux, L. Airoldi, H. Autrup et al., Amount of DNA in plasma and cancer risk: a prospective study, Int. J. Cancer, vol.111, pp.746-749, 2004.

E. Gudowska-nowak, K. Psonka-anto?czyk, K. Weron, T. Elsässer, and G. Taucherscholz, Distribution of DNA fragment sizes after irradiation with ions, Eur. Phys. J. E Soft Matter, vol.30, pp.317-324, 2009.

E. Hall and A. Giaccia, Radiobiology for the Radiologist, 7th Edn, 2011.

L. Hamon, D. Pastré, P. Dupaigne, C. Le-breton, E. Le-cam et al., High-resolution AFM imaging of single-stranded DNA-binding (SSB) protein-DNA complexes, Nucleic Acids Res, vol.35, p.58, 2007.

H. G. Hansma, K. Kasuya, and E. Oroudjev, Atomic force microscopy imaging and pulling of nucleic acids, Curr. Opin. Struct. Biol, vol.14, pp.380-385, 2004.

H. G. Hansma, D. E. Laney, M. Bezanilla, R. L. Sinsheimer, and P. K. Hansma, Applications for atomic force microscopy of DNA, Biophys. J, vol.68, pp.1672-1677, 1995.

H. G. Hansma, L. I. Pietrasanta, R. Golan, J. C. Sitko, M. B. Viani et al., Recent highlights from atomic force microscopy of DNA, J. Biomol. Struct. Dyn, vol.17, pp.271-275, 2000.

P. W. Hawkes, The Beginning of Electron Microscope, 1985.

L. J. Herrera, S. Raja, W. E. Gooding, T. El-hefnawy, L. Kelly et al., Quantitative analysis of circulating plasma DNA as a tumor marker in thoracic malignancies, Clin. Chem, vol.51, pp.113-118, 2005.

S. Holdenrieder, A. Burges, O. Reich, F. W. Spelsberg, and P. Stieber, DNA integrity in plasma and serum of patients with malignant and benign diseases, Ann. N.Y. Acad. Sci, vol.1137, pp.162-170, 2008.

S. Ido, K. Kimura, K. Oyabu, K. Kobayashi, M. Tsukada et al., Beyond the helix pitch: direct visualization of native DNA in aqueous solution, ACS Nano, vol.7, pp.1817-1822, 2013.

T. J. Jenner, M. Belli, D. T. Goodhead, F. Ianzini, G. Simone et al., Direct comparison of biological effectiveness of protons and alphaparticles of the same LET. III. Initial yield of DNA double-strand breaks in V79 cells, Int. J. Radiat. Biol, vol.61, pp.631-637, 1992.

K. Jung, M. Fleischhacker, and A. Rabien, Cell-free DNA in the blood as a solid tumor biomarker-a critical appraisal of the literature, Clin. Chim. Acta, vol.411, pp.1611-1624, 2010.

A. A. Kamat, M. Baldwin, D. Urbauer, D. Dang, L. Y. Han et al., Plasma cell-free DNA in ovarian cancer: an independent prognostic biomarker, 1918.

A. A. Kamat, F. Z. Bischoff, D. Dang, M. F. Baldwin, L. Y. Han et al., Circulating cell-free DNA: a novel biomarker for response to therapy in ovarian carcinoma, Cancer Biol. Ther, vol.5, pp.1369-1374, 2006.

C. Ke, Y. Jiang, P. A. Mieczkowski, G. G. Muramoto, J. P. Chute et al., Nanoscale detection of ionizing radiation damage to DNA by atomic force microscopy, vol.4, pp.288-294, 2008.

M. Kobayashi, K. Sumitomo, and K. Torimitsu, Real-time imaging of DNA-streptavidin complex formation in solution using a highspeed atomic force microscope, Ultramicroscopy, vol.107, pp.184-190, 2007.

R. Lal, J. , and S. A. , Biological applications of atomic force microscopy, Am. J. Physiol, vol.266, issue.1, pp.1-21, 1994.

D. E. Lea, Actions of Radiations on Living Cells, 1955.

G. Lee, G. G. Muramoto, J. P. Chute, and P. E. Marszalek, Nanomechanical fingerprints of gamma radiation damage to DNA, J. Nanosci. Nanotechnol, vol.9, pp.7359-7363, 2009.

J. T. Lett, Damage to cellular DNA from particulate radiations, the efficacy of its processing and the radiosensitivity of mammalian cells. Emphasis on DNA double strand breaks and chromatin breaks, Radiat. Environ. Biophys, vol.31, pp.257-277, 1992.

D. Levin and F. Hutchinson, Neutral sucrose sedimentation of very large DNA from Bacillus subtilis. I. Effect of random double-strand breaks and centrifuge speed on sedimentation, J. Mol. Biol, vol.75, issue.73, pp.90454-90457, 1973.

Y. L. Lyubchenko, A. A. Gall, and L. S. Shlyakhtenko, Visualization of DNA and protein-DNA complexes with atomic force microscopy, Methods Mol. Biol, vol.1117, pp.367-384, 2014.

D. M. Marzese, H. Hirose, and D. S. Hoon, Diagnostic and prognostic value of circulating tumor-related DNA in cancer patients, Expert Rev. Mol. Diagn, vol.13, pp.827-844, 2013.

A. K. Mazur and M. Maaloum, Atomic force microscopy study of DNA flexibility on short length scales: smooth bending versus kinking, Nucleic Acids Res, vol.42, pp.14006-14012, 2014.
URL : https://hal.archives-ouvertes.fr/hal-01498043

R. Mead, M. Duku, P. Bhandari, and I. A. Cree, Circulating tumour markers can define patients with normal colons, benign polyps, and cancers, Br. J. Cancer, vol.105, pp.239-245, 2011.

E. Mladenov, S. Magin, A. Soni, and G. Iliakis, DNA double-strand break repair as determinant of cellular radiosensitivity to killing and target in radiation therapy, Front. Oncol, vol.10, p.113, 2013.

F. Mouliere, S. El-messaoudi, C. Gongora, A. S. Guedj, B. Robert et al., Circulating cell-free DNA from colorectal cancer patients may reveal high KRAS or BRAF mutation load, Transl. Oncol, vol.6, pp.319-328, 2013.
URL : https://hal.archives-ouvertes.fr/hal-00872683

F. Mouliere, S. El-messaoudi, D. Pang, A. Dritschilo, and A. R. Thierry, Multi-marker analysis of circulating cell-free DNA toward personalized medicine for colorectal cancer, Mol. Oncol, vol.8, pp.927-941, 2014.
URL : https://hal.archives-ouvertes.fr/inserm-01076572

F. Mouliere, B. Robert, E. Arnau-peyrotte, M. Del-rio, M. Ychou et al., High fragmentation characterizes tumourderived circulating DNA, PLoS ONE, vol.6, 2011.

F. Mouliere and A. R. Thierry, The importance of examining the proportion of circulating DNA originating from tumor, microenvironment and normal cells in colorectal cancer patients, Expert Opin. Biol. Ther, vol.12, 2012.

M. Murakami, H. Hirokawa, and I. Hayata, Analysis of radiation damage of DNA by atomic force microscopy in comparison with agarose gel electrophoresis studies, J. Biochem. Biophys. Methods, vol.44, p.49, 2000.

H. Nikjoo, D. E. Charlton, and D. T. Goodhead, , 1994.

, Monte Carlo track structure studies of energy deposition and calculation of initial DSB and RBE, Adv. Space Res, vol.14, pp.90466-90475

A. D. Nygaard, K. L. Spindler, N. Pallisgaard, R. F. Andersen, J. et al., The prognostic value of KRAS mutated plasma DNA in advanced non-small cell lung cancer, Lung Cancer, vol.79, pp.312-317, 2013.

P. L. Olive, The comet assay. An overview of techniques, Methods Mol. Biol, vol.203, pp.179-194, 2002.

M. G. Ormerod and A. R. Lehmann, Artefacts arising from the sedimentation of high molecular weight DNA on sucrose gradients, Biochim. Biophys. Acta, vol.247, pp.90021-90030, 1971.

G. R. Oxnard, C. P. Paweletz, Y. Kuang, S. L. Mach, A. O'connell et al., Noninvasive detection of response and resistance in EGFRmutant lung cancer using quantitative next-generation genotyping of cell-free plasma DNA, Clin. Cancer Res, vol.20, pp.1698-1705, 2014.

R. B. Painter, Repair in mammalian cells: overview, Basic Life Sci, vol.5, pp.595-600, 1975.

D. Pang, B. L. Berman, S. Chasovskikh, J. E. Rodgers, and A. Dritschilo, Investigation of neutron-induced damage in DNA by atomic force microscopy: experimental evidence of clustered DNA lesions, Radiat. Res, vol.150, pp.612-618, 1998.

D. Pang, J. E. Rodgers, B. L. Berman, S. Chasovskikh, and A. Dritschilo, Spatial distribution of radiation-induced double-strand breaks in plasmid DNA as resolved by atomic force microscopy, Radiat. Res, vol.164, pp.755-765, 2005.

D. R. Pilch, O. A. Sedelnikova, C. Redon, A. Celeste, A. Nussenzweig et al., Characteristics of gamma-H2AX foci at DNA doublestrand breaks sites, Biochem. Cell Biol, vol.81, pp.123-129, 2003.

W. K. Pogozelski, M. A. Xapsos, and W. F. Blakely, Quantitative assessment of the contribution of clustered damage to DNA double-strand breaks induced by 60Co gamma rays and fission neutrons, Radiat. Res, vol.151, pp.442-448, 1999.

K. M. Prise, M. Folkard, H. C. Newman, and B. D. Michael, Effect of radiation quality on lesion complexity in cellular DNA, Int. J. Radiat. Biol, vol.66, pp.537-542, 1994.

K. Psonka, S. Brons, M. Heiss, E. Gudowska-nowak, and G. Taucher-scholz, Induction of DNA damage by heavy ions measured by atomic force microscopy, J. Phys. Condens. Matter, vol.17, pp.1443-1446, 2005.

K. Psonka-antonczyk, T. Elsässer, E. Gudowska-nowak, and G. Taucher-scholz, Distribution of double-strand breaks induced by ionizing radiation at the level of single DNA molecules examined by atomic force microscopy, Radiat. Res, vol.172, pp.288-295, 2009.

B. Rydberg, Clusters of DNA damage induced by ionizing radiation: formation of short DNA fragments, Radiat Res, vol.145, pp.200-209, 1996.

S. Santos, V. Barcons, H. K. Christenson, D. Billingsley, W. A. Bonass et al., Stability, resolution, and ultra-low wear amplitude modulation atomic force microscopy of DNA: small amplitude small set-point imaging, Appl. Phys. Lett, vol.103, p.63702, 2013.

M. Schafer, C. Schmitz, and H. Bucker, Heavy ion induced DNA double strand breaks in cells of E. coli, Adv. Space. Res, vol.14, issue.94, pp.90468-90473, 1994.

D. C. Schwartz and C. R. Cantor, Separation of yeast chromosomesized DNAs by pulsed field gradient gel electrophoresis, Cell, vol.37, pp.67-75, 1984.

H. Schwarzenbach, D. S. Hoon, and K. Pantel, Cell-free nucleic acids as biomarkers in cancer patients, Nat. Rev. Cancer, vol.11, pp.426-437, 2011.

O. A. Sedelnikova, D. R. Pilch, C. Redon, and W. M. Bonner, Histone H2AX in DNA damage and repair, Cancer Biol. Ther, vol.2, pp.233-235, 2003.

I. Sorel, O. Piétrement, L. Hamon, S. Baconnais, E. L. Cam et al., The EcoRI-DNA complex as a model for investigating protein-DNA interactions by atomic force microscopy, Biochemistry, vol.45, pp.14675-14682, 2006.

M. Stroun, J. Lyautey, C. Lederrey, A. Olson-sand, and P. Anker, About the possible origin and mechanism of circulating DNA: apoptosis and active DNA release, Clin. Chim. Acta, vol.313, pp.665-674, 2001.

G. Taucher-scholz, J. Heilmann, M. Schneider, and G. Kraft, Detection of heavy-ion-induced DNA double-strand breaks using staticfield gel electrophoresis, Radiat. Environ. Biophys, vol.34, pp.101-106, 1995.

C. D. Town, K. C. Smith, and H. S. Kaplan, DNA polymerase required for rapid repair of x-ray-induced DNA strand breaks in vivo, Science, vol.172, pp.851-854, 1971.

B. G. Wang, H. Y. Huang, Y. C. Chen, R. E. Bristow, K. Kassauei et al., Increased plasma DNA integrity in cancer patients, Cancer Res, vol.63, pp.3966-3968, 2003.

J. F. Ward, The complexity of DNA damage: relevance to biological consequences, Int. J. Radiat. Biol, vol.66, pp.427-432, 1994.

, Conflict of Interest Statement: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest