Rat Thiostatin ELISA

Thiostatin is a major protease inhibitor in serum and an acute phase protein that increases significantly in concentration in the rat as a result of inflammation. The major pathophysiological role for rat thiostatin has yet to be conclusively defined.

In this assay the thiostatin present in a sample reacts with the anti-thiostatin antibodies which have been adsorbed to the surface of polystyrene microplate wells. After the removal of unbound serum proteins by washing, anti-thiostatin antibodies conjugated with horseradish peroxidase (HRP) are added. These enzyme-labeled antibodies form complexes with the previously bound sample thiostatin. 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 thiostatin in the sample tested; the absorbance at 450 nm is a measure of the concentration of thiostatin in the sample. The quantity of thiostatin in the sample can be interpolated from the standard curve constructed from the standards, and corrected for serum dilution.