Osteocalcin ELISA Kit: Gla-Type Osteocalcin (Gla-OC) EIA Kit

The Takara Bio Osteocalcin ELISA Kit offers sensitive detection of the osteogenic marker osteocalcin (OC). OC, also known as gamma-carboxyglutamic acid protein, is a small (5.9 kDa), vitamin K-dependent, hydroxyapatite (Ca²⁺)-binding protein synthesized exclusively by osteoblasts and odontoblasts. The tissue-specific expression of OC makes it an excellent osteogenic marker for measuring osteoblast activity during bone formation. Osteocalcin is also a hormone that controls the regulation of glucose and fat deposition and plays a role in male fertility. Three gamma-carboxyglutamic acid (Gla) residues at positions 17, 21, and 24 of the protein are responsible for binding calcium. OC calcium-binding is also required for such biological activities as activation of the blood coagulation cascade. Carboxylated OC (Gla-OC) is most likely the active form of the protein, while decarboxylated OC (Glu-OC), which has weak hydroxyapatite affinity, represents the inactive form. Gla-OC versus Glu-OC serum levels correlate well with bone formation; thus, the Takara Bio human osteocalcin ELISA kit provides a better analysis of bone growth and remodeling than conventional assays that do not differentiate between the active and inactive protein forms.