Differentiation of MDFs into islet-like clusters. Single-cell derived MDF clones (Clone 27 and 45) exhibited a spindle-shaped morphology in culture (A) and formed cell clusters after 14 days of pancreatic induction (B). The cell clusters were positive for anti-insulin (C, red color) and anti-C-peptide (D, red color) antibody staining. Single cells from cell clusters were also positive for anti-C-peptide (E, red color) antibody staining. The nucleus is stained with DAPI (blue). Cell clusters and positive antibody staining were not observed in Clone 46, with or without induction. Scale bars, 100 μm.