Effects of I-2 knockdown and hesperadin on phosphorylation of Histone H3(S10). (A) Cells were transfected with I-2 siRNA or control siRNA for 48 h, treated with 200 or 300 nM hesperadin, respectively, for 2 h, and then they were fixed and stained with Hoechst 33342 (blue) and anti-phosphosite antibody for S10 in histone H3 (H3S10; orange). Bar, 25 μm. (B) The integrated intensity of H3S10 staining was quantified relative to Hoechst 33342 staining for individual mitotic cells. The graph shows the mean ± SD of the integrated intensity of H3S10 staining of 30 mitotic cells from three independent experiments (10 cells each experiment) of each treatment. *, p < 0.001.