The mouse osteocalcin ELISA from Takara Bio permits concurrent assay of both mouse undercarboxylated glutamate (Glu)-osteocalcin and gamma carboxyglutamate (Gla)-osteocalcin. Osteocalcin is a vitamin K-dependent calcium-binding non-collagenous protein found in bone and dentin. Unmodified Glu-type osteocalcin is produced by osteoblasts and is converted to active Gla-type osteocalcin; its binding to the bone matrix is enabled through the enzymatic conversion of glutamic acid to carboxyglutamate. The two forms of the molecule are present in the blood at levels that are thought to be related to bone metabolism. Bone turnover can also be analyzed by simultaneously measuring Gla-type and Glu-type osteocalcin. Recent findings suggest that Glu-type osteocalcin may also play an important role in the metabolism of sugar.
Gla-osteocalcin and Glu-osteocalcin can be assayed concurrently with the Mouse Gla-Osteocalcin High Sensitive EIA Kit (Cat. # MK127) and Mouse Glu-Osteocalcin High Sensitive EIA Kit (Cat. # MK129), respectively. These mouse osteocalcin ELISA kits allow for the relative evaluation of Gla/Glu-osteocalcins, thereby providing a measure of both bone formation and bone resorption.
These kits use a sandwich ELISA strategy to specifically detect the Gla and Glu forms of osteocalcin. The capture antibody is a plate-bound solid-phased rat monoclonal antibody that specifically recognizes the C-terminal region of mouse osteocalcin. This is paired with labeled monoclonal antibodies that are specific for recognized Glu-type or Gla-type osteocalcin. Because mouse osteocalcin has C terminal sequences that differ from other mammals, it is possible to measure mouse osteocalcin without any cross-reaction with bovine antigens with antibodies that recognize C-terminal epitopes. Therefore, the process of osteoblastic cell differentiation can be monitored in pluripotent cells, such as mouse ES and iPS cells, without interference from bovine serum included in the culture medium. Furthermore, these kits can be used for high-sensitivity measurements from a variety of samples, including cell culture supernatants, blood, or body fluids.