Stem Cells Characterization
Undifferentiated embryonic stem (ES) and induced pluripotent stem (iPS) cells can be functionally characterized by the ability to differentiate into cells of the three germ layers. In addition to the ability to give rise to all cell types, a number of molecular markers have been identified to verify the pluripotent status of stem cells. For example, human pluripotent stem cells express the cell surface proteins SSEA-4 and Alkaline Phosphatase and the transcription factors Oct-3/4 and Nanog. The ability to verify stem cell pluripotency using established markers at the start of an experiment helps ensure that downstream stem cell proliferation and differentiation studies are conducted on high quality, undifferentiated starting cell populations.