One focus of my laboratory is the in vitro maturation of human oocytes and their subsequent use for embryonic stem (ES) cell research. Somatic cell nuclear transfer into unfertilized eggs offers the possibility of creating human ES cells whose genetic makeup matches that of the recipient. In addition to providing a powerful research tool for understanding human disease, this approach may eventually allow patients to be treated with an unlimited supply of new cells that will be recognized as 'self,' thereby avoiding the serious problem of rejection by the body's own immune defenses. In order for progress to be made on this front, a steady supply of human oocytes is needed. However, acquiring sufficient oocytes from donors undergoing requisite fertility treatments with no reproductive or medical benefit to themselves is problematic for both ethical and logistical reasons. Our contribution to this effort will be to isolate human oocytes from discarded sources and to mature them in vitro with the ultimate goal of their development for use in somatic cell nuclear transfer. Additionally, the concepts and methods we use should be applicable to fertility preservation for patients undergoing therapies that damage the ovaries and for IVF patients who need to avoid hormonal stimulation prior to oocyte retrieval.