Research involving osteoclasts has always been difficult to undertake owing to a lack of osteoclast supply. Osteoclasts are terminally differentiated cells and, therefore, they cannot simply divide and be maintained in culturean osteoclast supply must constantly be replenished. Osteoclasts are large, multinucleated cells formed by the fusion of osteoclast precursors found in the monocyte fraction of blood. The osteoclast is thought to be the only cell capable of excavating authentic resorption lacunae in calcified substrates in vivo and in vitro.
