Fig. 3

Progenitor cells isolated from the low-energy traumatized muscle have the ability to undergo adipogenic, osteogenic, and chondrogenic differentiation. Representative images are shown from a control cells compared to cells induced to differentiation for 4 weeks followed by b Oil Red O staining (adipogenic induction), c Alizarin red staining (osteogenic induction), and d Alcian blue staining (chondrogenic induction). Multiprogenitor cells cultured in adipogenic induction medium demonstrated intracellular lipid droplets that stained positively for Oil Red O. Multiprogenitor cells cultured in osteogenic induction medium exhibited enhanced mineralized matrix formation that stained positively for Alizarin red staining. Histological sections of the multiprogenitor cell pellet cultures showed a positive matrix staining with Alcian blue, demonstrating the presence of sulfated proteoglycan-rich extracellular matrix. Images are at ×20 magnification