<p>Global 5-mC and 5-hmC levels were measured by ELISA-based assays in primary human fibroblasts at 6 and 24 h after X-ray irradiation with 2 and 4 Gy, respectively. For each time point and dose, the number of analyzed cultures is given in parenthesis. Results are presented as mean (of different cultures) over means (triplicate measurements) ± standard error. Asterisk denotes a significant (p < 0.05) between-group difference.</p
