Morphology of differentiated osteoclast cells. May Grunwald-Giemsa staining of (A) multinucleated osteoclasts and (B) MC3T3-E1 cells. Both cells were subjected to cytospin at day 3, 5, 7 or 10 differentiations prior to May Grunwald-Giemsa staining. The figure shows that the numbers of multinucleated osteoclast cells increased upon differentiation of mononucleated cells but not MC3T3-E1 cells. The black arrows show the multinucleated osteoclasts (400× magnification).