Fibrinogen ELISA

In this assay the fibrinogen (FIB) present in samples reacts with the anti-fibrinogen antibodies which have been adsorbed to the surface of polystyrene microtiter wells. After the removal of unbound proteins by washing, anti-fibrinogen antibodies conjugated with horseradish peroxidase (HRP), are added. These enzyme-labeled antibodies form complexes with the previously bound fibrinogen. Following another washing step, the enzyme bound to the immunosorbent is assayed by the addition of a chromogenic substrate, 3,3’,5,5’-tetramethylbenzidine (TMB). The quantity of bound enzyme varies directly with the concentration of fibrinogen in the sample tested; thus, the absorbance, at 450 nm, is a measure of the concentration of fibrinogen in the test sample. The quantity of fibrinogen in the test sample can be interpolated from the standard curve constructed from the standards and corrected for sample dilution.