The Corning Osteo Assay surface is an inorganic crystalline calcium phosphate coating on a polystyrene plate designed to mimic in vivo bone environment. The surface is intended to facilitate a variety of bone cell assays including immunofluorescent staining, tartrate resistant acid phosphatase (TRAP), and surface resorption assays for osteoclasts. The surface is available in a convenient, ready to use, sterile, multiple well plate and is stable at room temperature.