Abstract
To measure the radiation damage, γ-H2AX foci in the irradiated human peripheral lymphocytes and mouse organ tissues were detected as fluorescent signals, since phosphorylation of H2AX at serine 139 (γ-H2AX) occurs following DNA double strand- but not single-strand break induction and is probably the earliest manifestation of the lesion. Human peripheral lymphocytes and mice were exposed to 0, 0.1, 0.2, 0.5, 1, 2 Gy (1 Gy/min) of γ-rays. The γ-H2AX foci were detected dose dependently as fluorescent signals in both cells at 15 minutes after irradiation. These results suggest that quantitation of DSBs by the γ-H2AX foci is an useful biodosimeter for detecting high and low dose radiation damage in human being and mice. It is also suggested that there is a threshold dose which can not be discriminated the additional radiation induced DSBs from spontaneous DSBs in a cell. [J Radiat Res 44:406 (2003)]
