Human sTfR ELISA is a sandwich enzyme immunoassay for the quantitative measurement of soluble human transferrin receptor in serum, plasma and tissue culture medium.
Standards, quality controls and samples of sera are incubated in microtitration wells coated with monoclonal anti-human sTfR antibody. After a thorough wash, monoclonal anti-human sTfR antibody labeled with horseradish peroxidase (HRP) is added to the wells and incubated with the immobilized antibody'sTfR complex. Following another washing step, the remaining HRP-conjugated antibody is allowed to react with the substrate H2O2 and tetramethylbenzidine. The reaction is stopped by addition of acidic solution, and absorbance of the resulting yellow color product is measured spectrophotometrically at 450nm. The absorbance is proportional to the concentration of sTfR. A standard curve is constructed by plotting absorbance values versus recombinant sTfR concentrations of standards, and concentrations of unknown samples are determined using this standard curve.