In this study, we compared the effects of gamma and high-energy proton radiation (1000 MeV) on DNA in aqueous saline solutions (5 and 150 mM NaCl) at doses of 30 and 50 Gy. We used spectral methods (the ultraviolet absorption method, spectrophotometric methods for nucleic acid quantification, spectrophotometric DNA melting, and circular dichroism) for the estimation of the number of damaged nitrogenous bases and damage of the secondary DNA structure. It was found that under these conditions, proton radiation causes more severe destruction of nitrogenous bases and the secondary DNA structure than exposure to gamma rays at the same dose. In DNA irradiated with protons, the formation of crosslinks is possible and the probability for crosslinking increases with the increase of the ionic strength of the irradiated solution.

在这项研究中，我们比较了剂量为 30 和 50 Gy 的伽马和高能质子辐射 (1000 MeV) 对盐水溶液（5 和 150 mM NaCl）中 DNA 的影响。我们使用光谱方法（紫外吸收法、核酸定量分光光度法、分光光度法 DNA 熔解和圆二色性）来估计受损含氮碱基的数量和二级 DNA 结构的损伤。发现在这些条件下，质子辐射对含氮碱基和二级 DNA 结构的破坏比暴露于相同剂量的伽马射线更严重。在用质子照射的 DNA 中，有可能形成交联，并且随着照射溶液离子强度的增加，交联的可能性也增加。