Unique Features

  • Easy to perform
  • Sample volume only 20 μL
  • Measures bone formation in rat serum and plasma
  • Low sample volume 20 μL
  • Multi-disciplinary use – measuring plasma and serum samples
  • A complete assay panel supporting bone research

The Rat-MID Osteocalcin EIA is an enzyme-linked immunosorbent assay for the quantitative determination of osteocalcin in rat serum and plasma. The assay is for research use only.

The clinical utility of rat osteocalcin as a marker for bone turnover has been evaluated in several preclinical settings. It has been reported that the serum level increases after ovariectomy and this oestrogen deficiency-induced state can be prevented by treatment with either oestrogen, selective oestrogen receptor modulators (SERMs) or bisphosphonates1, 2, 3.

Osteocalcin or bone Gla protein (BGP) is a major non-collagenous protein of the bone matrix. It has a molecular weight of approximately 6000 Dalton and consists in most species of 49 amino acids; however, rat osteocalcin consists of 50 amino acids.

Osteocalcin has a unique property for binding to calcium facilitated by the presence of 2-3 gamma-carboxyglutamic acids at position 17, 21 and 24. The mid-molecular part of osteocalcin, especially the amino acids between 20 and 30, exhibits a high degree of inter-species conservation.

The Rat-MID Osteocalcin EIA is based upon the competitive binding of a monoclonal antibody to soluble osteocalcin or to immobilised osteocalcin. Briefly, the monoclonal antibody is raised against human osteocalcin and recognizes the mid-molecular part (amino acids 21-29) of the molecule.

O’Sullivan S et al., Imatinib mesylate does not increase bone volume in vivo. Calcif Tissue Int. 2011 Jan;88(1):16-22.

Schaller S et al., The chloride channel inhibitor NS3736 [corrected] prevents bone resorption in ovariectomized rats without changing bone formation. J Bone Miner Res. 2004 Jul;19(7):1144-53.

Schaller S et al., In vitro, ex vivo, and in vivo methodological approaches for studying therapeutic targets of osteoporosis and degenerative joint diseases: how biomarkers can assist? Assay Drug Dev Technol. 2005 Oct;3(5):553-80.