Fig. 2. Immunolocalization of total and `activated' <sub>v</sub>ß<sub>3</sub> integrin in non-resorbing human osteoclasts. Primary human OCs were plated on coverslips in the presence of 10% FBS and immunostained for total <sub>v</sub>ß<sub>3</sub> with mAb AP3 (A) or with AP5 (C), which binds specifically to the `activated' conformation. Cells were co-stained with F-PHD for actin (B,D). Total _vß₃ is found in rosette-like structures clustered around actin cores (Fig. 2A,B, insert) and in the motile parts of the plasma membrane (arrow). The `activated' conformation of the integrin detected by AP5 (C) is clustered in the motile region of the plasma membrane, corresponding to ruffles and lamellipodia. At the periphery, as indicated by the arrow (Fig. 2C, insert), the integrin appears as a continuous line that colocalizes with the actin fibers (Fig. 2D, insert). Bar, 10 µm.