sTfR Human ELISA (soluble Transferrin Receptor)

Research topic

Iron metabolism

Features

• The total assay time is less than three hours.
• The kit measures total serum transferrin receptor.
• Quality controls are human serum based. No animal sera are used.
• Components of the kit are ready-to-use (with the exception of Wash Solution).

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

The transferrin receptor (TfR) is the gateway for transferrin-bound-iron entering all body cells. TfR is abundant on the surface of many newly formed cells, but the erythroid marrow cells account for 70 to 80 % of the total body TfR content. The soluble (or serum) transferrin receptor (sTfR) is a circulating truncated form of the membrane receptor protein; it is an 85 kDa glycoprotein forming in serum a 320 kDa complex with diferric transferrin. The serum sTfR concentration reflects the total body mass of cellular transferrin receptor. Anaemias associated with enhanced erythropoiesis and iron deficiency result in an elevation in the sTfR values. The normal sTfR concentrations are about 1.0 – 2.9 μg/ml for adults, when using this assay, the iron deficiency may increase the values up to 20 fold (various normal values have been established by other producers for their assays). Elevation of the soluble transferrin receptor may be also caused by haemolytic anaemia, polycythaemia and thalassemia while aplastic anaemia and chronic renal failure may result in decrease. The most important clinical use of the sTfR determination is in the differential diagnosis between iron deficiency anaemia and the anaemia of chronic disease.

Assay format

Sandwich ELISA, HRP-labelled antibody

Sample requirements

10 µl/well

Applications

Cell culture medium, Plasma-Citrate, Plasma-EDTA, Plasma-Heparin, Serum

Calibration Curve

Calibration range

0.05 – 2 µg/ml

Limit of detection

Analytical Limit of Detection is calculated from the real human sTfR values in wells and is 10ng/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 = 10ng/ml x 10 = 100ng/ml

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

CV = 4.0 %

Inter-assay (Run-to-Run, n=4)

CV = 4.1 %

Spiking Recovery

96 %

Dilution Linearity

102 %

Cross-Reactivity

Human, Dog, Goat, Monkey, Pig

References to this product

• Fernandez-Real JM, Moreno JM, Lopez-Bermejo A, Chico B, Vendrell J, Ricart W . Circulating soluble transferrin receptor according to glucose tolerance status and insulin sensitivity. Diabetes Care . Mar;30(3):604-8 (2007)

References to summary

• Raya G. et al.: Soluble transferrin receptor (sTfR): biological variations and reference limits. Clinical Chemistry and Laboratory Medicine, 39, 1162–1168 (2001)
• Cotton F. et al.: Measurement of soluble transferrin receptor by immunoturbidimety and immunonefelometry. Clinical Biochemistry, 33, 263–267 (2000)
• Cook J. D.: The measurement of serum transferrin receptor. The American Journal of the Medical Sciences 318, 269–276 (1999)
• Olivares M. et al.: Usefulness of serum transferrin receptor and serum ferritin in diagnosis of iron deficiency in infancy. American Journal of Clinical Nutrition 72, 1191–1195 (2000)
• Suominen P. et al.: Single values of serum transferrin receptor and transferrin receptor ferritin index can be used to detect true and functional iron deficiency in rheumatoid arthritis patients with anemia. Arthritis & Rheumatism 43, 1016–1020 (2000)
• De Block C. E. M. et al.: Soluble transferrin receptor level. A new marker for iron deficiency anemia, a common manifestation of gastric autoimmunity in type 1diabetes. Diabetes Care 23, 1384–1388 (2000)
• Kolbe-Busch S. et al. Determination of the soluble transferrin receptor in Serum: Evaluation of two enzyme immunoassays and a particle-enhanced immunonephelometric assay. Clinical Laborators 45, 295–304 (1999)
• Hikawa A. et al.: Soluble transferrin receptor-transferrin complex in serum: measurement by latex agglutination nephelometric asssay. Clinica Chimica Acta 254, 159–172 (1996)
• Flowers C. H. et al.: The clinical measurement of serum transferrin receptor. Journal of Laboratory and Clinical Medicine 114, 368–377 (1989)