Percentage of micronuclei formation, observed by fluorescent microscopy (1000x) after Hoechst staining. (A) MCF-10A and (B) MCF-7 cell lines 24 hours after 0.003; 0.012; 0.048 Gy/28 kV and 5 Gy/30 Kv X-ray irradiation. (C) Example of a cell containing a micronucleus formed after irradiation. Paired t-test with 95% confidence intervals were performed on the irradiated samples of each type of cell line in comparison to its corresponding mock control. Student’s t test * P ≤ 0.05.