Anti-Factor IX Antibody

This rabbit polyclonal antibody from Antibodies.com specifically targets human Factor IX, also called Christmas factor, a vitamin K-dependent serine protease zymogen with a molecular weight around 57 kDa that drives the intrinsic pathway of blood coagulation. Factor IX is synthesized in hepatocytes and circulates in plasma before being activated by the Factor XIa feedback loop or the tissue factor–Factor VIIa complex on phospholipid surfaces; activated Factor IX then assembles with Factor VIIIa, calcium, and phospholipid to convert Factor X into Factor Xa.

Supplied as 100 µl of unconjugated antiserum, the reagent is validated for Western blot and immunohistochemistry on human samples. It supports research into hemophilia B (Christmas disease), deep vein thrombosis, liver biology, and recombinant clotting-factor therapeutics, and the unconjugated format lets investigators conjugate the antibody to their preferred reporter enzyme or fluorophore for custom detection workflows. In Western blot, it is useful for tracking recombinant Factor IX expression in transfected cell lines, while in IHC it serves as a hepatocyte marker because Factor IX expression is largely liver-restricted.

Because the antibody is polyclonal, it recognizes multiple epitopes across the target, which improves detection of both full-length zymogen and activation fragments generated during purification or coagulation studies. Aliquoting upon first use helps preserve activity across repeated freeze-thaw cycles, and standard cold-chain handling in a sealed vial keeps the reagent stable for long-term bench use.