Fig. 1

A priming dose of 0.5 Gy protected lung fibroblasts from DNA damage caused by a subsequent 2.0 Gy dose administered 24 h later. Representative images (a) and quantification (b) of tail moments in WI-38 cells at 1 h post 2 Gy irradiation. Thirty cells at least were analyzed in each group. Quantification is represented as values expressed as fold change relative to control (Ctrl). (c) Classification of DNA damage. A bar graph was used to show the distribution of cells among three DNA damage levels. Two independent experiments were conducted. The level of significance was represented as *P < 0.05, Student’s t-test.