Maintenance of undifferentiated state of human embryonic stem cells in chemical defined medium at high clone density without exogenous cell factors

To establish human embryonic stem cells (hESCs) feeder-independent and cell factor-free culture system. Effect of high and low clone densities of hESCs culture was compared and impact of the clone densities to hESCs culture media was analyzed. HESCs could maintain their undifferentiated states at high clone density (34 clones/cm²) without cell factors. At the same time, the bone morphology protein (BMP)-like induction of N2 and B27 supplements (NB) medium could be modulated by the clone density, and high level of BMP-like induction was accompanied by high clone density. High clone density of hESCs can change the environments by themselves to maintain the undifferentiated states, which provides a new clue to explore the mechanism of undifferentiated states of hESCs and simplify the culture medium.