Factor XIIIa (Coagulation Factor XIII A Chain, Coagulation Factor XIIIa, Coagulation Factor XIII A1 Polypeptide, F13A, F13A1, bA525O21.1, Fibrinoligase, Protein-glutamine gamma-glutamyltransferase A Chain, Transglutaminase A Chain, TGase)

Coagulation factor XIII is the last zymogen to become activated in the blood coagulation cascade. Plasma factor XIII is a heterotetramer composed of 2 A subunits and 2 B subunits. The A subunits have catalytic function, and the B subunits do not have enzymatic activity and may serve as plasma carrier molecules. Platelet factor XIII is comprised only of 2 A subunits, which are identical to those of plasma origin. Upon cleavage of the activation peptide by thrombin and in the presence of calcium ion, the plasma factor XIII dissociates its B subunits and yields the same active enzyme, factor XIIIa, as platelet factor XIII. This enzyme acts as a transglutaminase to catalyze the formation of gamma-glutamyl-epsilon-lysine crosslinking between fibrin molecules, thus stabilizing the fibrin clot. It also crosslinks alpha-2-plasmin inhibitor, or fibronectin, to the alpha chains of fibrin. Factor XIII deficiency is classified into two categories: type I deficiency, characterized by the lack of both the A and B subunits; and type II deficiency, characterized by the lack of the A subunit alone. These defects can result in a lifelong bleeding tendency, defective wound healing, and habitual abortion. Antibody Titer: Precipitin titer not less than 1:32 when tested against appropriate concentrations of the antigen in agar-block immunodiffusion titration. The titre is further assayed by quantitative precipitin analysis incubating serial dilutions of the antiserum with normal plasma and measuring the residual antigen. The amount of Factor XIII precipitated by 1ml antiserum is about 10U. Applications: Suitable for use in ELISA, Immunoelectrophoresis, Immunoelectrodiffusion and Radial Immunodiffusion (single and double). Other applications not tested. Recommended Dilution: Immunoelectrophoresis (agarose plates): 120ul antiserum per 2ul plasma or equivalent Double Radial Immunodiffusion: Use a rosette arrangement with 10ul antiserum in 3mm diameter center well and 2ul plasma samples (neat and serially diluted) in 2mm diameter peripheral wells. Electroimmunodiffusion: 1-2% antiserum depending on the test arrangement. Optimal dilutions to be determined by the researcher. Storage and Stability: Lyophilized powder may be stored at -20 degrees C. Stable for 12 months at -20 degrees C. Reconstitute with sterile ddH2O. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Reconstituted product is stable for 12 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.