This sandwich ELISA kit uses two anti-human FGF23 mouse monoclonal antibodies. When serum is added to a plate well coated with anti-human FGF23 mouse monoclonal antibodies, FGF23 is captured by the immobilized antibodies (1st reaction). After the 1st reaction, the plate is washed. Then, ALP-labeled anti-human FGF23 mouse monoclonal 2nd antibodies against FGF23 react to FGF23 antigens captured by the immobilized antibodies (2nd reaction). After the 2nd reaction, the plate is washed and light detection is performed after adding the luminescence reagent. Each active well of the plate is measured using a luminescence microplate reader and relative light units (RLU) are obtained. The concentration of FGF23 in serum is calculated with a standard curve generated using the FGF23 Standard 1 to 6. Sample Types: serum. Range: 15-3000 pg/mL. Time: 2.5 hours ? FGF23 (Fibroblast Growth Factor 23) is a protein belonging to the fibroblast growth factor family. FGF23 is involved in the regulation of phosphorus metabolism. FGF23 has a molecular weight of approximately 32 kDa. FGF23 is produced in bone cells. In vivo, FGF23 is secreted into circulation. A full-length active FGF23 protein may undergo proteolytic cleavage to generate an inactive c-terminal fragment. This mechanism is thought to play a key role in controlling the concentration of circulating bioactive FGF23 in vivo.