Effect of X- and Gamma Rays on DNA in Human Cells

The purpose of this study was to investigate the effect of different doses and dose rates of x-rays and Co-60 gamma rays on DNA in normal human mononuclear cells. The cells were irradiated with x-ray doses (0.25, 0.5, 1, 2, 4) Gy at dose rate 0.28 Gy/min or with doses (15.625, 31.25, 62.5, 125, 250) mGy at dose rate 20 mGy/min or with X-ray doses (0.25, 0.5, 1, 2, 4 Gy at dose rate 2Gy/hr. The amount of 8-oxoguanine were detected by fluorescein-isothiocyanate (FITC) labeled antibodies. Using flow cytometry, the number of 8-oxoguanine /cell was calculated by calibration using spheric particles. Significant damage of DNA was observed for both x and rays. We concluded that DNA damage depends on dose and dose rate, and it is good biomarker for radiation response.