Efficient expansion of HPC/PBMC-derived iPSC clones under feeder- and serum-free conditions. (a) Long-term time-lapse images of an iPSC HPC-A1 colony were obtained by using Nikon BioStation IMQ. Time is shown in hours in the upper right corner, and cell count is shown in the bottom right corner of each panel. (b) Frequent mitotic events were observed during time-lapse imaging. Dividing cells and daughter cells are indicated by yellow and green arrows. Time is shown in minutes in the upper right corner of each panel. (c) High-magnification images of a dividing cell at different stages of mitosis (prophase, prometaphase, metaphase, anaphase, and telophase) are indicated in green arrows. Time is shown in minutes in the upper right corner of each panel.