Immunofluorescence staining for extracellular matrix proteins in day 1 and day 7 HWJSC spheroids.

<p>HWJSC spheroids were cultured for either 1 day or 7 days (with 6 days of osteogenic differentiation), fixed, and stained for extracellular matrix proteins: collagen I (A) collagen IV (B), laminin (C), and fibronectin (D) and counter-staining with Hoechst. Scale bars represent 100 μm.</p>