Comet assay in the assessment of the human genome damage induced by γ-radiation in vitro

Abstract

Background. The aim of the present study was to estimate a possible application of comet assay in the evaluation of DNA damage caused by different gamma radiation doses in peripheral human lymphocytes in vitro.

Materials and methods. Whole blood samples of young healthy, non-smoking donors were taken. The samples were divided in 4 specimens. The first specimen was used as the control. Other three specimens were irradiated using constant gamma irradiation source (60Co) giving the dose rate of 0.907 cGy/s. Different specimens were irradiated for 51 s, 437 s and 1099 s, giving the doses of 0.5 Gy, 4 Gy and 10 Gy. In order to estimate dose-response curve on the control and all 3 irradiated whole blood samples, the comet assay under alkali conditions was performed.

Results and conclusions. The comet assay endpoints showed statistically significantly higher values for all irradiated blood samples compared to the control. For both, tail length and tail moment, dose-effect relationship was found to be linear in a dose range of 0.5Gy and 10 Gy. By this work we also pointed out possible usage of the comet assay in the detection of DNA lesions caused by extremely high radiation dose, which is not possible by using standard cytogenetic methods.