Figure 1. Cell fusion between EGFP-positive and EGFP-negative osteoclasts. RAW 264.7 cells were transfected with EGFP-actin and induced osteoclastogenesis by adding RANKL. The osteoclasts were processed for time lapse confocal microscopy as described.⁵ Images were retrieved every 2 min. Upper panel, DIC images. Lower panel, EGFP images. At 90 min, a stalk-like link appeared between two cells at the contact area (arrow). Bar, 50 µm.