DescriptionFactor X Paired Antibody Set Affinity’s Factor X Paired Antibody Set consists of matched capture and detecting antibodies that have been titrated and optimized for use in sandwich style ELISA assays. The product as provided contains sufficient capture and detecting antibodies for five full 96-well microplates and contains a detailed protocol sheet containing directions for use, recipes for solutions and sources for additional materials required. This Factor X Paired Antibody Set is intended to facilitate the end user in establishing an “in-house” immunoassay for research purposes only and must not be used for diagnostic applications.  Assay validation is the responsibility of the end user.Product Code: FX-EIASupplied Materials: Capture Antibody (FX-EIA-C): One yellow-capped vial containing 0.5 ml of polyclonal affinity purified anti-Factor X antibody for coating plates.Detecting Antibody (FX-EIA-D):  One red-capped tube containing 0.5 ml of peroxidase conjugated affinity-purified polyclonal anti-Factor X antibody for detection of captured Factor X .Related Products: VisuLize Buffer Pak VisuCal Antigen Calibrator PlasmaSpecies Cross Reactivity: View ChartProduct Datasheet: Factor X F10 Matched Pair Antibody Set for ELISADescription of Factor X (FX)Factor X (FX, Stuart Factor) is a vitamin K-dependent glycoprotein produced in the liver. The concentration of FX in plasma is ~10 μg/ml (~170 nM). Factor X is expressed as a two-chain molecule with a molecular weight of 59 kDa. The light chain (17 kDa) of FX contains a calcium-binding domain consisting of one hydroxy-aspartic acid and 11 γ-carboxyglutamic acid (gla) residues. These residues allow F.X to bind to membranes that contain acidic phospholipids in a calcium dependent manner. This is followed by two EGF-like domains. The heavy chain of FX (42 kDa) consists of the catalytic domain, carbohydrate and the activation peptide. Activation of FX to the active enzyme (FXa) results from cleavage at residue Arg52 in the heavy chain of F.X by a complex of F.IXa, cofactor VIIIa, calcium and negatively charged phospholipid surface (the tenase complex), or by the F.VIIa-tissue factor complex. Both activation pathways result in the release of the activation peptide from the N-terminal of the heavy chain. The FXa generated is a serine protease responsible for the activation of prothrombin to thrombin in the presence of a phospholipid membrane, calcium and cofactor Va. The activity of FXa in plasma is inhibited by antithrombin (ATIII), α1antitrypsin, α2macroglobulin and tissue factor pathway inhibitor (TFPI). The inhibitory activity of ATIII is stimulated approximately 1000-fold by heparin1-3.References and ReviewsIchinose A, Davie EW; The Blood Coagulation Factors: Their cDNAs, Genes, and Expression; in Hemostasis and Thrombosis, 3rd Edition, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp 19-54, J.B. Lippincott Co., Philadelphia PA, USA, 1994.Steinberg M, Nemerson Y; The Activation of Factor X; in Hemostasis and Thrombosis, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp 91-99, J.B. Lippincott Co., Philadelphia PA, USA, 1982.Ellis V, Scully M, MacGregor I, Kakkar V; Inhibition of Human Factor Xa by Various Plasma Protease Inhibitors; Biochimica et Biophysica Acta 701, pp 24-31, 1982.