Figure 5

Osteogenic differentiation of pancreatic mesenchymal stem cells. Tissue collected after 20 days of treatment with osteo-selective medium had abundant alkaline phosphatase (AP) activity stained red (a), some evidence of mineralization stained black by Von Kossa (VK) staining at the left edge of the section (c) and collagen deposition stained green by Gomori's Trichrome stain (e). Immunohistochemical staining for osteocalcin is positive (brown) using the immunoperoxidase method (g). VK stain and osteocalcin are counterstained with hematoxylin (blue). Tissue collected at 31 days of treatment had scant AP activity (b), a significant increase in mineralization stained black (d) compared to images (a and c), overlying the tissue that is composed entirely of collagen, stained green by Trichrome stain (f). Immunohistochemical staining for osteocalcin is still positive (h). Immunoperoxidase stain is brown and hematoxylin counterstain is blue. Scale bar represents 100 μm.