A quantitative ELISA-based assay for Human Osteoprotegrin (OPG). Each kit contains: an anti-Human Osteoprotegrin sensitized 96-strip micro-well plate (break-away strips) , 50mL diluent, 50 mL (20X) wash solution, anti-Human Osteoprotegrin conjugate, 12mL TMB substrate, 12mL stop solution and a Human Osteoprotegrin calibrator.