Fetuin-A (AHSG) Human ELISA

Research topic

Bone and cartilage metabolism, Renal disease

Features

• The total assay time is less than 3 hours.
• The kit measures serum or plasma Fetuin-A.
• Calibrator is human plasma based.
• Quality Controls are human serum based.
• Components of the kit are provided ready-to-use, concentrated and lyophilized.

Storage/Shipping

Store the kit at 2–8°C. Under these conditions, the kit is stable until the expiration date (see label on the box).

Summary

Fetuin-A (AHSG), a 59 kDa glycoprotein, consisting of two cystatin-like domains and a smaller unrelated domain, is predominantly sinthetized in liver . It is secreted into the blood stream and deposited as a noncollagenous protein in mineralized bones and teeth. Fetuin-A occurs in high serum concentrations during foetal life, whereas its level declines following infection, inflamatory and malignancy. Fetuin-A acts as an important circulating inhibitor of ectopic calcification, frequent complication of many degenerative diseases. Low serum level of Fetuin-A is associated with vascular and valvular calcification, atherosclerosis, malnutrition and higher cardiovascular mortality in chronic renal failure, liver cancer and liver cirrhosis patients on long-term dialysis. AHSG protein represents a natural inhibitor of tyrosinase kinase activity of the insulin receptor. It may play a significant role in regulating postprandial glucose disposal, insulin sensitivity, weight gain, and fat accumulation. The serum and bone-resident Fetuin-A binds to transforming growth factor- β and blocks TGF-β binding to cell surface receptors.

Assay format

Sandwich ELISA, HRP-labelled antibody

Sample requirements

10 µl/well

Applications

Serum

Calibration Curve

Limit of detection

Analytical Limit of Detection is calculated from the real Fetuin-A values in wells and is 0.35 ng/ml

Limit of quantification

Assay Sensitivity takes the dilution of samples into consideration and is calculated according to the formula: Assay Sensitivity = Analytical Limit of Detection x sample dilution = 0.35 ng/ml x 10 000 = 3.50 μg/ml

Intra-assay (Within-Run, n=8)

CV = 3.5 %

Inter-assay (Run-to-Run, n=5)

CV = 5.4 %

Spiking Recovery

102.8 %

Dilution Linearity

95.9 %

Cross-Reactivity

Human, Goat

References to this product

• Stefan N, Hennige AM, Staiger H, Machann J, Schick F, Krober SM, Machicao F, Fritsche A, Haring HU . Alpha2-Heremans-Schmid glycoprotein/fetuin-A is associated with insulin resistance and fat accumulation in the liver in humans. Diabetes Care . Apr;29(4):853-7 (2006)
• Mori K, Emoto M, Araki T, Yokoyama H, Teramura M, Lee E, Motoyama K, Koyama H, Shoji T, Inaba M, Nishizawa Y . Association of serum fetuin-A with carotid arterial stiffness. Clin Endocrinol (Oxf) . Feb;66(2):246-50 (2007)
• Mori K, Emoto M, Yokoyama H, Araki T, Teramura M, Koyama H, Shoji T, Inaba M, Nishizawa Y . Association of serum fetuin-A with insulin resistance in type 2 diabetic and nondiabetic subjects. Diabetes Care . Feb;29(2):468 (2006)
• Caglar K, Yilmaz MI, Saglam M, Cakir E, Kilic S, Eyileten T, Sonmez A, Oguz Y, Oner K, Ors F, Vural A, Yenicesu M . Endothelial dysfunction and fetuin A levels before and after kidney transplantation. Transplantation . Feb 27;83(4):392-7 (2007)
• Kaden JJ, SuselbeckT, Brueckmann M, Poerner T, Borggrefe M, Ortlepp JR . Erniedrigte Fetuin-Serumspiegel bei kalzifizierender Aortenklappenstenose. Z Kardiol . 94 (2005); Suppl 1, poster P442
• Ziolkowska H, Wojnar J, Panczyk-Tomaszewska M, Roszkowska-Blaim M . Fetuin A in children with renal diseases. Przegl Lek . 63 Suppl 3:54-6 (2006)
• Jung HH, Kim SW, Han H . Inflammation, mineral metabolism and progressive coronary artery calcification in patients on haemodialysis. Nephrol Dial Transplant . Jul;21(7):1915-20 (2006)
• Pertosa G, Simone S, Russo R, Marrone D, Porreca S, Schena FP, Grandaliano G . Low serum levels of fetuin-A and inflammation are associated with altered bone metabolism and enhance cardiovascular risk in dialysis patients (PTS). Nephrology . 10 (Suppl.), A117-A232 (2005)
• Stejskal D, Karpisek M, Vrtal R, Student V, Solichova P, Fiala R, Stejskal P. Urine fetuin-A values in relation to the presence of urolithiasis. BJU Int. 2008 May;101 (9):1151-4

References to summary

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• Schinke T., Amendt C., Trindl A., Poeschke O., Mueller-Esterl W., Jahnen-Dechent W.: The serum protein alpha2-HS glycoprotein/fetuin inhibits apatite formation in vitro and in mineralizing calvaria cells. A possible role in mineralization and calcium homeostasis. J Biol Chem 1996; 271: 20789–96
• Osawa M., Umetsu K., Sato M., Ohki T., Yukawa N., Suzuki T., Takeichi S.: Structure of the gene encoding human alpha 2-HS glycoprotein. Gene 1997; 196: 121–125
• Mathews S. T., Chellam N., Srinivas P. R., Cintron V. J., Leon M. A., Goustin A. S., Grungerger G.: Alpha2-HSG, a specific inhibitor of insulin receptor autophosphory­lation, interacts with the insulin receptor. Moll Cell Endocrinol 2000; 164: 87–98
• Heiss A., DuChesne A., Denecke B., Grotzinger J., Yamamoto K., Renne T., Jahnen-Dechent W.: Structural basis of calcification inhibition by alpha 2-HS glycoprotein/fetuin-A: formation of colloidal calciprotein particles. J Biol Chem 2003; 278: 13333–13341
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