Effect of MIG on adhesion of osteoclast precursors and TRAP⁺ osteoclasts. (A) Osteoclast precursors were treated with 50 ng/mL M-CSF for 60 to 72 hours. Cells were incubated for 10 minutes on fibronectin-coated culture plates supplemented with the indicated concentration of MIG. Nonadherent cells were washed with PBS, and adherent cells were stained with hematoxylin and counted under a light microscope. ^*Significant difference from the medium control (P < .01). (B) Osteoclast precursors were treated with 50 ng/mL M-CSF plus 100 ng/mL RANKL for 60 to 72 hours. Cells were added to the vitronectin-coated culture plates, supplemented with the indicated concentration of MIG, and incubated for 10 minutes. Adhesion assays were performed as described. ^*Significant difference from the medium control (P < .01). (C) Osteoclast precursors from wild-type mice and GFP-transgenic mice were treated with 50 ng/mL M-CSF plus 100 ng/mL RANKL for 60 to72 hours. GFP-expressing cells were then transferred to dishes containing non-GFP cells and were incubated for 1 hour in the presence or absence of 100 ng/mL MIG. Dishes were washed to remove unbound cells, and the number of bound cells was scored under a fluorescence microscope. ^*Significant difference from the medium control (P < .01).