Thopan Prutchayawoot, Yu Liangdeng, Brown Ian G, Tippawan Udomrat
a Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
b Thailand Center of Excellence in Physics, Commission on Higher Education, Bangkok 10400, Thailand.
Radiat Res. 2017 Oct;188(4):426-432. doi: 10.1667/RR14721.1. Epub 2017 Aug 2.
The goal of this study was to determine the critical ion-radiation conditions under which heavy ion beams can induce DNA double-strand breaks. Helium, nitrogen and argon-ion beams in the energy range of 20 eV to 2 keV were used to irradiate naked DNA plasmid pGFP to fluences of 1, 2 and 4 × 10 ions/cm. The topological forms of DNA were subsequently analyzed using gel electrophoresis. The DNA forms were changed from the original supercoiled to damaged relaxed and linear forms, depending on the ion mass, energy, fluence and inertia. We found ion energy and fluence thresholds above which direct double-strand breaks can occur. The threshold is discussed in terms of the areal ion-energy density and the cross-section.
本研究的目的是确定重离子束能够诱导DNA双链断裂的关键离子辐射条件。使用能量范围为20 eV至2 keV的氦离子、氮离子和氩离子束辐照裸露的DNA质粒pGFP，使其通量达到1、2和4×10离子/cm。随后使用凝胶电泳分析DNA的拓扑形式。DNA形式从原始的超螺旋形式转变为受损的松弛形式和线性形式，这取决于离子质量、能量、通量和惯性。我们发现了离子能量和通量阈值，超过该阈值会发生直接双链断裂。根据面离子能量密度和横截面讨论了该阈值。
