Figure 7. Evaluation of cardiomyocyte cell cycle via immunostaining for phosphorylated histone H3.

Cell cycle was assessed by immunostaining using antibodies against phosphorylated histone H3 (PH3) (to label cells in mitosis phase). Cardiomyocytes were labeled using anti-human cTnT immunostaining; all nuclei were counterstained with DAPI. The prevalence of PH3 positively stained nuclei of hiPSC-CMs was counted and normalized to the total number of cardiomyocyte nuclei. Data were presented as percentage. (A) Representative images of anti-PH3 immunostaining in hiPSC-CMs. (B) Quantification of the prevalence of PH3 positively stained nuclei of hiPSC-CMs after siRNA-based knockdown. All data were presented as mean ± SEM. Statistical analysis was performed via 1-way ANOVA with Tukey’s honestly significant difference test. n = 30 technical replicates in each group. *P < 0.05, and ****P < 0.0001.