The percentage of proliferating cells at 24hr was evaluated with an EdU [23] assay (Click-iT Plus EdU Imaging kit, MAN0009885, Molecular Probes, by Life Technologies) according to the manufacturer’s instructions. The rate of expansion of iPS cells and NPCs was determined by plating 7.5×105 cells in separate wells of 6-well plates and by replenishing the media (mTeSR or expansion growth medium, respectively) daily. At each passage (p), the cells were harvested and the total cell number was calculated on the basis of amplification rate at each passage. The logarithmic value of the total viable-cell number was plotted against the days, starting from the beginning of the experiment. For each condition, growth curves were performed in duplicate, but a representative curve is reported.
