Figure 1: Example of Diff-Quik stained undifferentiated cASCs with flattened fibroblast-like morphology (a). After 5 weeks of osteogenic induction, von Kossa staining was positive, showing large black calcifying nodules (b). Chondrogenic differentiated cASCs show polygonal morphology after 21 days of induction in addition to positive Alcian blue staining of the chondrocyte-specific glycosaminoglycans (c). In (c) an adherent double cell layer is to be seen. Adipogenic induction could be shown 23 days after induction by positive red lipid droplets after Oil Red O staining (d). Scale bar: 200 μm (a–c) and 100 μm (d).