Patent ID: 8871504

Claim:
A method of identifying a clonal induced pluripotent stem (iPS) cell line that is not resistant to differentiation comprising the steps of: (1) culturing cells of a clonal iPS cell line in retinoic acid such that differentiation occurs; (2) culturing the cells obtained in step (1) under conditions for maintaining pluripotent stem cells such that colonies of pluripotent stem cells occur; (3) determining the number of colonies of pluripotent stem cells in the cells obtained in step (2); and (4) identifying a clonal iPS cell line as being not resistant to differentiation when the number of colonies determined in step (3) is less than or equal to the number of colonies of pluripotent stem cells obtained when an equal number of embryonic stem (ES) cells are cultured under the same conditions as in steps (1) and (2).