Fig. 2

X-ray photon irradiation induced nuclear DNA damage and activated the DNA repair pathway. a Micrographs of single and double strand DNA breaks from alkaline comet assay at 72 h post-irradiation. Round cells indicate intact DNA, comet tails indicate DNA strand breaks. Violin plot shows median (solid line) length of comet tail (pixels) ± interquartile range (dotted line) of N = 50–73 comets per RT. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 as determined by Kruskal–Wallis with Dunn’s multiple comparison test. b Dot plot of DNA repair indicate by phosphorylated ATM (pATM) and H2A.X (γ-H2A.X) at 72 h post-irradiation. Column graphs show mean percentage (%) ± SEM of duplicates from three independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 vs 0 Gy determined by two-way ANOVA with Dunnett’s multiple comparison test. c Immunoblot of γH2A.X (Ser139), mono-ubiquitinated γH2A.X (γH2A.X-ub₁), and reference protein β-actin at 72 h post-irradiation. Band intensity was data standardised to β-actin per sample and then expressed relative to 0 Gy. Raw data is provided in Additional file 4: Fig. S2. Column graph shows mean fluorescent intensity relative to 0 Gy ± standard deviation (SD) of from three independent experiments