Bone resorption assay

Mature osteoclasts were prepared from co-cultures of bone marrow cells and primary osteoblasts on collagen gel-coated culture dishes, as described previously.⁵⁸ For the bone resorption assay, BMMs and mature osteoclasts were cultured on Osteo Assay Surface plates (Corning) for 6 days and 12 h, respectively, coated with vehicle (DMSO), vitronectin (0.23 μg/cm²), or synthetic peptide (9.1 μg/cm²) in the presence of 30 ng/ml M-CSF and 100 ng/ml RANKL. The cells were removed using 10% Clorox (0.56% NaOCl), and the resorbed pits were photographed and analyzed using the Image Pro-Plus program (version 4.0; Media Cybernetics).