Patent ID: 7964402

Claim:
A method of preparing human embryonic stem cells comprising (a) providing a culture of human embryonic stem (ES) cells and (b) enzymatically dissociating the culture of human embryonic stem cells using a mixture of enzymes with proteolytic, collagenolytic, and DNAse activities to produce a plurality of single embryonic stem cells, wherein greater than 75 percent of said plurality of single embryonic stem cells are viable and pluripotent, and wherein the single embryonic stem cells do not experience a decrease in plating efficiency upon repeated passaging when compared to single human ES cells that are dissociated without the use of a mixture of enzymes with proteolytic, collagenolytic, and DNAse activities, and wherein a greater proportion of said plurality of single ES cells are undifferentiated when compared to ES cells produced by collagenase digestion of a culture of ES cells.