Avoid freeze/thaw cycles as they may denaturate the polypeptide chains of the antibody, thus reducing its reactivity, specificity and sensitivity. For antibodies that are in liquid form or reconstituted lyophilized antibodies small amounts could become entrapped on the seal or the walls of the tube. Prior to use briefly centrifuge the vial to gather all the solution on the bottom.
Thrombin is the final protease in the blood coagulation cascade and serves both pro- and anticoagulant functions through the cleavage of several targets. The ability of thrombin to specifically recognize a wide range of substrates derives from interactions which occur outside of the active site of thrombin. Thrombin possesses two anion binding exosites which mediate many of its interactions with cofactors and substrates, and although many structures of thrombin have been solved, few such interactions have been described in molecular detail. Glycosaminoglycan binding to exosite II of thrombin plays a major role in switching off the procoagulant functions of thrombin by mediating its irreversible inhibition by circulating serpins and by its binding to the endothelial cell surface receptor thrombomodulin.