Description
Principle of the Assay: The principle of the double antibody sandwich ELISA is represented in Figure 1. In this assay the Plasminogen present in samples reacts with the anti-Plasminogen antibodies which have been adsorbed to the surface of polystyrene microtitre wells. After the removal of unbound proteins by washing, anti-PMG antibodies conjugated with horseradish peroxidase (HRP), are added. These enzyme-labeled antibodies form complexes with the previously bound PMG. 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 PMG in the sample tested; thus, the absorbance, at 450 nm, is a measure of the concentration of PMG in the test sample. The quantity of PMG in the test sample can be interpolated from the standard curve constructed from the standards, and corrected for sample dilution.
Background: Plasminogen (PMG) is a glycoprotein produced by the liver. It is the precursor for plasmin, which targets fibrin in the process of dissolution of fibrin blood clots. Plasminogen is present in plasma and most extravascular fluids. The important role of plasminogen in fibrinolytic system makes it an interesting marker for various diseases