Example of blebbistatin-treated ESC dividing at the periphery of a colony. Time-lapse (spinning-disk confocal microscopy) of a colony of ESCs expressing H2BRFP (red) and labelled with CellMaskTM deep red (cyan) and treated with 1 μM Blebbistatin with one cell dividing at the periphery of the colony. The cell displays strong size asymmetry between daughter cells. One frame is shown every 5 min. One Z plane is shown. Scale bar: 10 μm.