Workflow for cell cycle synchronization and validation of PARI depletion efficiency by siRNA. (A) Top: Experimental workflow to synchronize siRNA-transfected cells and inducing catenated chromatin bridges during cytokinesis by the addition of ICRF-193 during G2. Bottom: Flow cytometry analysis of DNA content in siCtrl and siPARI-1 cells at the indicated times after G1 release. (B) RT-qPCR measures the mRNA levels of PARI in HeLa cells after transfecting twice with 25 nM siCtrl, siPARI-1, and siPARI-2. Relative mRNA levels have been normalized to siCtrl. One-sample t and Wilcoxon test (mean ± SD, ****P < 0.0001, N = 4).