Morphology and bone resorbing activity of osteoclasts. (A) TRAP staining of osteoclasts differentiated according to the culture D schedule are shown. (B) The pits formed in the dentine slice used in the experiment for first column of Table 2, indicating bone resorbing activity of osteoclasts, are shown. (C) A colony from a single ES cell generated by the culture D schedule was stained for TRAP⁺ cells and photographed. Note that TRAP⁺ cells appear in the circular edge, not inside of the colony. Scale bars: 50 μm in (A) and (B), 400 μm in (C).