Figure 3.

Ca²⁺ deposition induced by the classical pathway of osteogenesis in the presence of TEA in SaOS-2 cells. Ca²⁺ deposits were stained using alizarin red S (see Materials and Methods). Alizarin red S-stained cultures were photographed with a microscope equipped with a digital camera. The photos are presented according to the time of the examination by the rows and the type of treatment by the columns. Column I.: non-differentiated cell cultures (Ctrl, no differentiation cocktail) on Day 3 (row (A)), Day 4 (row (B)) and on Day 5 (row (C)). Column II.: differentiated cells (Diff, classical induction pathway cocktail) after the osteogenic induction in the same order as above. Column III.: differentiated cells in the presence of TEA (1 mM TEA, classical induction pathway cocktail+1 mM TEA) in the same order as above. The hydroxyapatite containing bone nodules are recognizable with the red color.