Osteoprotegerin ELISA Kit (OPG)

Full Name: Osteoprotegerin ELISA Kit (OPG)
Reactivity: Human
Sample Type: Serum, Tissue Homogenates, Plasma, Biological Fluids
Sensitivity: 37.5 pg/ml


Osteoprotegerin (OPG) contains a cysteine-rich domain, a transmembrane domain, and a TNF receptor-like domain. This structure allows it to bind to and inhibit the activity of receptor activator of nuclear factor-kappa B ligand (RANKL). RANKL is involved in bone remodelling and the activation of immune cells and its activity is regulated by OPG. It is highly expressed in the skeleton and is secreted by osteocytes. It is produced by osteoblasts and stromal cells which allows it to regulate bone homeostasis through suppressing RANKL activity. The major circulating isoform is the 734-amino acid form (sOOPG) which has a molecular weight of 80 kDa. Smaller forms, such as the 435-amino acid form (uSOPG), have been identified in circulation but their biological functions are currently unknown. As with other members of its tyrosine protein kinase family.

In the bone osteoprotegerin helps to regulate bone remodelling by binding to RANKL and preventing it from stimulating osteoclast activity. It is important for maintaining bone density and strength. The body’s production of OPN decreases by 30% in cancer patients but increases again when the cancer is cured. In vitro studies using mouse cells have shown that exposure to RANKL can stimulate human OPN gene transcription. It is expressed in many tissues including the lungs, spleen, and joints. It also plays a role in inflammation, wound healing and bone formation. It is a dimer of two identical proteins, OPN1 and OPN2. It is produced by the bone marrow and released into the circulation. Osteoprotegerin binds to cell surface receptors including LFA-1, CD18, E-selectin and VLA-4. The carboxyl terminus of OPN1 (amino acids 1-50) contains a putative receptor binding site for one of the chemokine receptors CXCR3. The N-terminus appears to contain a site for binding to an unknown cofactor that will likely turn out to be a scaffold for a wide range of interactions.


Human osteoprotegerin ELISA kit is ideal for analysing OPG (osteoprotegerin, osteoclastogenesis inhibitory factor, TR1, TNFRSF11B) present in human serum, tissue homogenates, plasma and many other biological fluids.


All reagents supplied need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

  • One 96-Well Plate: Pre-coated with anti-OPG
  • Standards: Lyophilized recombinant.
  • Sample/Standard Dilution Buffer.
  • Biotinylated-labelled Antibody.
  • Antibody Dilution Buffer.
  • HRP-Streptavidin Conjugate (SABC).
  • SABC Dilution Buffer.
  • TMB Substrate.
  • Wash Buffer (25x).
  • Plate Sealer.
  • Product Instructions.


For this osteoprotegerin ELISA kit it is recommended that a standard curve is generated for each assay carried out.

Standard Curve: 0, 62.5, 125, 250, 500, 1000, 2000, 4000 pg/ml.
Reactivity: Human
Sensitivity: 37.5 pg/ml
Range: 62.5 – 4000 pg/ml
Principle: Sandwich
Application: Research Use Only.


– Specificity: Highly specific for OPG, no cross reactivity or interference between OPG and analogues was detected.
– Recovery: Serum (91 – 105%), EDTA Plasma (85 – 105%), Heparin Plasma (88 – 104%).
– Linearity: Serum (84 – 100%), EDTA Plasma (87 – 95%), Heparin Plasma (83 – 101%).
– Precison Intra-Assay: CV < 8%.
– Precison Inter-Assay: CV < 10%.
– Stability: Less than 10%.


  1. The role of osteoprotegerin in cardiovascular disease. Ann Med. (2013) 45 (3): 254-64. Montagnana M., et al.
  2. Osteoclast differentiation by RANKL and OPG signaling pathways. J Bone Miner Metab. (2021) 39 (1): 19-26. Udagawa N., et al.
  3. Inflammatory profile of chronic apical periodontitis: a literature review. Acta Odontol Scand. (2019) 77 (3): 173-180. Braz-Silva P.H., et al.
  4. Osteoprotegerin: multiple partners for multiple functions. Cytokine Growth Factor Rev. (2013) 24 (5): 401-9. Baud’huin M., et al.


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