Patent ID: 7217569

Claim:
A method of establishing a clonal human embryonic stem cell line capable of sustaining a phenotype of normal embryonic stem cells following prolonged in vitro culture, the method comprising the steps of providing a culture of undifferentiated human embryonic stem cells; removing an individual undifferentiated human embryonic stem cell in a separate culture which includes at least about 4 ng/ml of exogenously supplied human fibroblast growth factor and which is essentially free of mammalian serum; and culturing the individual undifferentiated cell in a serum-free medium which includes at least about 4 ng/ml of exogenously supplied human fibroblast growth factor such that the cell expands into a clonal culture of undifferentiated human embryonic stem cells maintaining the ability to differentiate into endoderm, mesoderm and ectoderm after at least six months of culture.