Definitive endoderm

Abstract

Disclosed herein are cell cultures comprising definitive endoderm cells and methods of producing the same. Also disclosed herein are cell populations comprising substantially purified definitive endoderm cells as well as methods for enriching, isolating and purifying definitive endoderm cells from other cell types.

What is claimed is: 
     
         1 . A cell culture, comprising:
 a medium comprising human pluripotent stem cells, definitive endoderm cells, and activin A,   wherein less than about 5% (v/v) of the medium is serum;   wherein activin A is present in an amount sufficient to differentiate the human pluripotent stem cells into definitive endoderm cells; and   wherein at least 10% of cells in the cell culture comprise definitive endoderm cells.   
     
     
         2 . The cell culture of  claim 1 , wherein said medium further comprises an effective amount of a BMP family member. 
     
     
         3 . The cell culture of  claim 2 , wherein said BMP family member is BMP4. 
     
     
         4 . The cell culture of  claim 1 , further comprising an effective amount of a Wnt family member. 
     
     
         5 . The cell culture of  claim 4 , wherein said Wnt family member is Wnt3a. 
     
     
         6 . The cell culture of  claim 1 , wherein said cell culture comprises at least 25 ng/ml activin A. 
     
     
         7 . The cell culture of  claim 1 , wherein said cell culture comprises at least 100 ng/ml activin A. 
     
     
         8 . The cell culture of  claim 6 , wherein less than about 2% (v/v) of said medium is serum. 
     
     
         9 . The cell culture of  claim 6 , wherein less than about 1% (v/v) of said medium is serum. 
     
     
         10 . The cell culture of  claim 6 , wherein less than about 0.5% (v/v) of said medium is serum. 
     
     
         11 . An in vitro method of producing human mesendoderm cells that express brachyury, the method comprising:
 (a) obtaining a cell population comprising human pluripotent stem cells; and   (b) culturing said cell population in a medium comprising at least 10 ng/ml activin A and about 0.05% to about 10% serum for a sufficient time to produce mesendoderm cells that express brachyury.   
     
     
         12 . The in vitro method of  claim 11 , wherein said medium comprises at least 30 ng/ml activin A. 
     
     
         13 . The in vitro method of  claim 11 , wherein said medium comprises at least 100 ng/ml activin A. 
     
     
         14 . The in vitro method of  claim 11 , wherein said human pluripotent stem cells comprise human embryonic stem cells.