The Eagle Biosciences Human Osteocalcin ELISA Assay Kit is designed, developed and produced for the quantitative measurement of of human osteocalcin (1-49) and (1-43) in serum or plasma sample. The assay utilizes the two-site ``sandwich'' technique with two selected antibodies that bind to different epitopes of human osteocalcin. Assay standards, controls and samples are added directly to wells of a microtiter plate that is coated with streptavidin. Subsequently, a mixture of biotinylated human osteocalcin N-terminal region specific polyclonal antibody and a peroxidase labeled human osteocalcin 20 - 43 region specific monoclonal antibody is added to each well. After the first incubation period, a ``sandwich'' of ``biotinylated antibody - human osteocalcin - HRP-monoclonal antibody'' is formed and this immunocomplex is also captured to the wall of microtiter plate via a streptavidin-biotin affinity binding. The unbound monoclonal antibodies and buffer matrix are removed in the subsequent washing step. A substrate solution in a timed reaction is then measured in a spectrophotometric microplate reader. The enzymatic activity of the immunocomplex bound to the wall of each microtiter well is directly proportional to the amount of human osteocalcin in a test sample. A standard curve is generated by plotting the absorbance versus the respective human osteocalcin concentration for each standard on point-to-point or 4 parameter curve fit. The concentration of human osteocalcin in test samples is determined directly from this standard curve. Sample Types: serum, plasma. Range: 4.0 - 64 ng/ml. Sensitivity:.31 ng/ml. Time: 1.5 hours ? The Eagle Biosciences Human Osteocalcin ELISA Assay Kit (enzyme-linked immunoassay kit) is intended for the quantitative determination of both human osteocalcin (1-49) and osteocalcin (1-43) (also referred as N-terminal & mid-regional osteocalcin) levels in test samples). The Eagle Biosciences Human Osteocalcin ELISA Assay Kit is for research use only and not to be used in diagnostic procedures.