Analysis of cell cycle. Panel A: Photographs of hESC at different densities. The table below is an analysis of cell cycle profile using EdU for 30 minutes at 10 uM. Note the differences in G1 and G2/M with different cell density. Using cells at 50-60% confluence is optimal. Lower Panel: Histogram of hESC treated with BRDU demonstrating a 50-60% of cells in S phase. Panel B: Flow cytometry histograms of cell cycle profile of hESC, human IPS cells, mouse IPS cells and Jurkat cells treated with EdU and DAPI. Note the red box highlights the mean intensity of EdU signal that can also be used as an indicator of the proliferative state of the cells.