Primate embryonic stem cells

Abstract

A purified preparation of primate embryonic stem cells is disclosed. This preparation is characterized by the following cell surface markers: SSEA-1 (−); SSEA-4 (+); TRA-1-60 (+); TRA-1-81 (+); and alkaline phosphatase (+). In a particularly advantageous embodiment, the cells of the preparation are human embryonic stem cells, have normal karyotypes, and continue to proliferate in an undifferentiated state after continuous culture for eleven months. The embryonic stem cell lines also retain the ability, throughout the culture, to form trophoblast and to differentiate into all tissues derived from all three embryonic germ layers (endoderm, mesoderm and ectoderm). A method for isolating a primate embryonic stem cell line is also disclosed.

1 - 11 . (canceled)  
     
     
         12 . A preparation of pluripotent human stem cells comprising cells which (i) are capable of proliferating in vitro culture for over one year, (ii) can maintain a karyotype in which the chromosomes are euploid through prolonged culture, (iii) can maintain the potential to differentiate to derivatives of endoderm, mesoderm, and ectoderm tissues throughout the culture, (iv) are inhibited from differentiation when cultured on a fibroblast feeder layer, and (v) are negative for the SSEA-1 cell surface marker and positive for the SSEA-1 cell surface marker.  
     
     
         13 . The preparation of  claim 12 , wherein the stem cells will spontaneously differentiate to trophoblast and produce chorionic gonadotropin when cultured to high density.  
     
     
         14 . A preparation of pluripotent human embryonic stem cells as claimed in  claim 12  wherein the cells express alkaline phosphatase activity.  
     
     
         15 . The preparation of  claim 14 , wherein the cells are positive for the TRA-1-60, and TRA-1-81 markers.  
     
     
         16 . The preparation of  claim 14 , wherein the cells will differentiate to trophoblast when cultured beyond confluence and will produce chorionic gonadotropin.  
     
     
         17 . The preparation of  claim 14 , wherein the cells remain euploid for more than one year of continuous culture.  
     
     
         18 . The preparation of  claim 14 , wherein the cells differentiate into cells derived from mesoderm, endoderm and ectoderm germ layers when the cells are injected into a SCID mouse.