Factor X (F.X) is a vitamin K-dependent glycoprotein produced in the liver. The concentration of F.X in plasma is ~10ug/ml (~170nM). Factor X is expressed as a two-chain molecule with a molecular weight of 59kD. The light chain (17kD) of F.X contains a calcium-binding domain consisting of one hydroxyaspartic acid and 11 gamma 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 F.X (42kD) consists of the catalytic domain, carbohydrate and the activation peptide. Activation of F.X to the active enzyme (F.Xa) 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 F.Xa 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 F.Xa in plasma is inhibited by antithrombin (ATIII), alpha1-antitrypsin, alpha2-macroglobulin and tissue factor pathway inhibitor (TFPI). The inhibitory activity of ATIII is stimulated ~1000-fold by heparin. Test Principle: Affinity-purified polyclonal antibody to FX is coated onto the wells of a microtiter plate. Any remaining binding sites on the plastic wells are blocked with an excess of bovine serum albumin. The plates are washed and plasma or other fluids containing FX are applied. The coated antibody will capture the FX in the sample. After washing the plate to remove unbound material, a peroxidase conjugated second antibody to FX is added to the plate to bind to the captured FX. After washing the plate to remove unbound conjugated antibody, the peroxidase activity is expressed by incubation with o-phenylenediamine (OPD). After a fixed development time the reaction is quenched with the addition of H2SO4 and the color produced is quantified using a microplate reader. The color generated is proportional to the concentration of FX in the sample. Materials Supplied: Antibodies for 5x96 well plates Kit Components: Capture Antibody, 1x500ul: affinity-purified polyclonal anti-FX antibody for coating plates. Detecting Antibody, 1x500ul: peroxidase conjugated polyclonal anti-FX antibody for detection of captured FX. Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 12 months after receipt. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
Form:
Supplied as a liquid in buffer, 50% glycerol.
* VAT and and shipping costs not included. Errors and price changes excepted
