Confocal microscopy confirmed that the anti-RANK receptor mAb staining (green color) was limited to surface receptors present on osteoclastic precursors as well as mature osteoclast-like cells (Fig. 6a) . Counterstaining with DAPI (blue color) confirmed the multinucleated phenotype of osteoclast-like giant cells. Nucleoli were also witnessed in the images. There was no demonstrable fluorescent fluorescein isothiocyanate (FITC) staining in negative control slides (Fig. 6b and c) . A commercially available anti-RANK mAb was used as a positive method control to confirm that RAW 264.7 osteoclastic precursors as well as mature osteoclast-like cells indeed stained for surface RANK receptors using immunocytochemistry.