Impact of RAD51 on SMC-targeting CRISPR/Cas9 knock-out process. (A) Compositional structure of mitotic cohesin; SMC3 is indicated in bright red. (B) Expression analysis of SMC3 targeted by CRISPR/Cas9. Protein levels were detected through immunoblot assay. (C) Quantification of SMC3 protein levels in (B). Relative SMC3 protein level to α-tubulin was normalized to the sample of non-transfected mock. Error bars indicate the mean ± SD (n = 3). Statistical significance, *P < 0.05, **P < 0.01, ***P < 0.001. (D) qPCR analysis of SMC3 gene in each CRISPR/Cas9 plasmid. The fold-change value was normalized to the numerical value of the non-transfected mock. Error bars indicate the mean ± SD (n = 3). (E) Cell viability assay to observe the effect of SMC3 depletion. Each cell sorting (live, injured, and dead cells) was based on the distributions of mock and H2O2-treated samples. (F) The proportion of each cell composition in indicated conditions was quantified.