Osteoclasts in Culture

Formation of multinucleated osteoclast-like cells in culture requires the addition of RANKL (receptor activator of NFkB ligand), a soluble secreted cytokine functioning in the final steps of osteoclast maturation. Here, RAW264.7 monocyte/macrophage cells show fusion (top) to form multinucleated giant cells with osteoclast function in vitro (bottom).