Description
Principle of the assay: This assay employs a two-site sandwich ELISA to quantitative F1+2 in Human serum, plasma. An antibody specific for F1+2 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any F1+2 present is bound by the immobilized antibody. After removing any unbound substances, a biotin - conjugated antibody specific for F1+2 is added to the wells. After washing, Streptavidin conjugated Horseradish Peroxidase (HRP) is added to the wells. Following a wash to remove any unbound avidin-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of F1+2 bound in the initial step. The color development is stopped and the intensity of the color is measured.
Background: Prothrombin is a carbohydrate-protein compound in plasma essential to coagulation. In response to bleeding, a complex series of clotting-factor interactions leads to its conversion by thromboplastin to thrombin, which transforms fibrinogen in plasma into fibrin. Fibrin and platelets combine to form a clot. Prothrombin and prothrombin fragment F1+2 (F1+2) were demonstrated in the tumor stroma on cancer cells and on small blood vessels in areas of neoangiogenesis at the host-tumor interface. F1+2 is an indicator of local activation of blood coagulation in cancer tissue. Thrombin itself is impossible to quantitate and so the use of surrogate markers is necessary. The measurement of F1+2 would be an excellent marker of thrombin generation. This is helped by the fact that F1+2 is not generated in vivo by any other mechanism. Fragment 1+2 has a half life of about 1 hour and is cleared from the bloodstream by the liver