An Analytical method for quantifying the yields of DNA double-strand breaks coupled with strand breaks by -H2AX focus formation assay based on track-structure simulation

Yachi, Yoshie*; Matsuya, Yusuke*  ; Yoshii, Yuji*; Fukunaga, Hisanori*; Date, Hiroyuki*; Kai, Takeshi   

When living cells are irradiated with radiation and complex damage is formed within a few nanometers of DNA, it is believed to induce biological effects such as cell death. In general, complex DNA damage formed in cells can be detected experimentally by fluorescence microscopy, because the area around the damage site emits light like a focus point when a fluorophore is used. However, this detection method has not been able to analyze the degree of complexity of DNA damage. Therefore, in this study, we addressed on the measured focus size and evaluated the degree of complexity of DNA damage using a track structure analysis code. As a result, we found that as DNA damage becomes more complex, the focus size also increases. Our findings are expected to provide a new analytical method for elucidating the initial factors of radiation biological effects.