Unique Features

  • Easy to perform
  • The N-MID® Osteocalcin ELISA recognises both intact and large N-Mid® osteocalcin fragments with equal affinity
  • N-MID® Osteocalcin ELISA measuring total osteocalcin is more stable and reproducible than assays measuring intact osteocalcin only
  • Robust assay format
  • Excellent correlation with automated methods
  • A complete clinical assay panel supporting bone disease management

The N-MID® Osteocalcin ELISA is an enzyme immunological test for the quantitative measurement of osteocalcin, an indicator of osteoblastic activity in human serum and plasma and is intended to be used as an aid in the prevention of osteoporosis.

Determination of serum osteocalcin has proved to be valuable as an aid in identifying women at risk of developing osteoporosis, for monitoring bone metabolism during the perimenopause and postmenopause and during anti-resorptive therapy1, 2, 3.

Osteocalcin, or bone Gla protein (BGP), is the major non-collagenous protein of bone matrix. It has a molecular weight of approximately 5800 Dalton and consists of 49 amino acids, including three residues of gamma-carboxyglutamic acid.

Osteocalcin is synthesised in bone by osteoblasts. After production, it is partly incorporated into the bone matrix and partly delivered to the circulatory system.

The precise physiological function of osteocalcin is still unclear. A large number of studies have shown that the circulating level of osteocalcin reflects the rate of bone formation.

The N-MID® Osteocalcin ELISA is based upon the application of two highly specific monoclonal antibodies (mAbs) against human osteocalcin. An antibody recognising the mid-region (amino acids 20-29) is used as the capture antibody, and for detection a peroxidase conjugated antibody recognising the N-terminal region (amino acids 10-16) is used. In addition to intact osteocalcin (amino acids 1-49) the N terminal mid-fragment (amino acids 1-43) is also detected.

Christiansen C. et al., Dose dependent effects on bone resorption and formation of intermittently administered intravenous ibandronate. Osteoporos Int (2003) 14: 609-613.

Tanko LB. et al., Oral ibandronate: changes in markers of bone turnover during adequately dosed continuous and weekly therapy and during different sub-optimally dosed treatment regimens. Bone (2003) 32: 687-693.

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.