For Research Use Only. Not for use in diagnostic procedures

Fibroblast growth factor 23 (FGF-23), which is produced by bone cells, is a novel member of a large family of related proteins. Its gene encodes a 251 amino acid protein. The amino-terminal portion of FGF-23 (aa 1-24) is hydrophobic and is likely to serve as a signal peptide allowing its secretion into the blood circulation. Its carboxyl-terminal portion (aa 180-251) shares only limited amino acid homology with other members of the FGF family of proteins. 

Renal phosphate wasting disorders leading to hypophosphatemia are among the causes of defective mineralization of bone and growth plate development. Patients with autosomal dominant hypophosphatemic rickets (ADHR), a rare genetic disorder, carry one of several different FGF-23 mutations that make the protein resistant to proteolytic cleavage. Furthermore, tumors that cause oncogenic osteomalacia (OOM) have been shown to overexpress FGF-23 mRNA making it likely that elevated concentrations of FGF-23 in the blood are the cause of renal phosphate wasting in this group of patients. FGF-23 levels have been shown to be elevated in renal disease. The concentration appears to correlate with the degree of bone mineralization and increasing levels have been shown to be a predictor of mortality in these patients. All currently available data suggest that FGF-23 is either directly or indirectly involved in the regulation of phosphate homeostasis.

This 2nd generation Human FGF-23 (C-Term) ELISA Kit is a two-site enzyme-linked immunosorbent assay (ELISA) for the measurement of FGF-23 in plasma or cell culture media. Two affinity purified goat polyclonal antibodies have been selected to detect epitopes within the carboxyl-terminal (C-Term) portion of FGF-23. One antibody is biotinylated for capture and the other antibody is conjugated with the enzyme horseradish peroxidase (HRP) for detection. These antibodies bind to both the intact molecule and large carboxyl terminal fragments of human FGF-23.