All ESC and iPSC lines possess the following qualities of “stemness”: They are undifferentiated, self-renewing, and remain pluripotent.  While there appears to be a trend towards accepting the demonstration of appropriate marker expression in undifferentiated cells as an indication of pluripotency, it has not been directly correlated with differentiation capacity in the literature to date.  In fact, there are several identified cell lines (including embryonic carcinoma cells, on which these markers were initially identified) that demonstrate marker expression but are nullipotent, as well as recently identified lines that show reduced Oct4 expression and yet retain the ability to create teratomas in-vivo.  For this reason, WiCell views the capacity for self-renewal/differentiation and pluripotency as separate and distinct traits, and assesses them independently.   

Undifferentiated State (Self-Renewal Assay)

Pluripotency Assay