Description
This Eagle Biosciences Human C-Terminal ELISA Assay Kit is designed, developed and produced for the quantitative measurement of human C-terminal FGF-21 in serum and EDTA-plasma sample. The assay utilizes the two-site “sandwich” technique with two selected antibodies that bind to different epitopes of human FGF-21. One of the antibodies specifically binds to the C-terminal human FGF-21 (175-181) and the other is to the multi-epitopes of mid-regional and N-terminal human FGF-21. Assay calibrators, controls and patient samples are added directly to wells of a microplate that is coated with an anti-human FGF-21 (175-181) specific antibody. After the first incubation period, a horseradish peroxidase-conjugated anti-human FGF-21 polyclonal antibody is added to each well. After the second incubation period, the antibody on the wall of microtiter well captures human C-terminal FGF-21 in the sample and further forms “sandwich” with the tracer antibody. Unbound proteins in each microtiter well are washed away. An immunocomplex of “anti-FGF-21 antibody --- human C-terminal FGF-21 --- HRP-conjugated tracer antibody” is formed. The unbound tracer antibody is removed in the subsequent washing step. For the detection of this immunocomplex, the well is then incubated with a substrate solution in a timed reaction and then measured in a spectrophotometric microplate reader. The enzymatic activity of the immunocomplex bound to human C-terminal FGF-21 on the wall of the microtiter well is directly proportional to the amount of C-terminal FGF-21 in the sample. A calibrator curve is generated by plotting the absorbance versus the respective human C-terminal FGF-21 concentration for each calibrator on point-to-point or 4 parameter curve fit. The concentration of human C-terminal FGF-21 in test samples is determined directly from this calibrator curve