Characterization of UCMSCs cultured with hepatogenic medium on untreated plastic support. (A) Undifferentiated and differentiated cell morphology. After 14 days of culture in differentiating medium we observed changes in cell morphology: cell spreading was reduced and the UCMSCs acquired a polygonal shape with a granular cytoplasm (B) Immunocytochemical analyses for α-fetoprotein (AFP) and albumin in UCMSCs cultured on untreated plastic support. The UCMSCs were cultured on petri dishes with proliferative (untreated) or differentiating medium. AFP protein expression was undetectable in both untreated and differentiated cells. Albumin protein was expressed by differentiated cells after 14 days but not by untreated cells. (C) Periodic acid-Schiff (PAS) staining for glycogen storage. UCMSCs cultured with differentiating medium on petri dishes displayed a positive reaction to PAS staining, revealing glycogen storage in their cytoplasm. Untreated cells were negative for PAS staining. Scale bar: 100 μm.