Oxygen tension for the parthenogenic activation of human oocytes for the production of human embryonic stem cells

A method of producing human stem cells comprising:

• a) parthenogenetically activating a human oocyte, wherein activating comprises:
• i) contacting the oocyte with an ionophore at high O2 tension and ii) contacting the oocyte with a serine-threonine kinase inhibitor under low O2 tension;
• b) cultivating the activated oocyte of step (a) at low O2 tension until blastocyst formation;
• c) transferring the blastocyst to a layer of feeder cells, and culturing the transferred blastocyst under high O2 tension;
• d) mechanically isolating an inner cell mass (ICM) from trophectoderm of the blastocyst of step (c);
• and
• e) culturing the cells of the ICM of step (d) on a layer of feeder cells, wherein culturing step (e) is carried out under high O2 tension, thereby producing human stem cells.