Osteo Assay Surface Polystyrene Stripwells (Corning, Corning, NY) were used to observe pit formation as a measure of osteoclast activity. Mouse BMMs (5 × 104 cells/well) were plated on stripwells and cultured in α-MEM complete media containing M-CSF (30 ng/ml), sRANKL (10 ng/ml or 100 ng/ml), DPB-LPS (1 μg/ml), and/or EETC (10 μg/ml). Cultures were fed every 2 days with fresh medium. After a 15-days incubation period, all remaining cells were lysed using 5% sodium hypochlorite solution. Images of the resorbed pits were obtained under light microscopy.