von Willebrand Factor (vWF, previously referred to as Factor VIII Related Antigen) is a large adhesive protein produced in endothelial cells and megakaryocytes. There are two critical functions of vWF. The first being its involvement in the process of platelet adhesion and aggregation through interaction with platelet receptor glycoprotein Ib. The second being the binding and stabilization of Factor VIII (anti-hemophilic factor) for secretion and transport in plasma. The vWF precursor protein is synthesized with a 95kD propeptide (also known as vWF antigen-II). The propeptide is believed to be involved in the intracellular multimerization of the vWF subunits. The mature vWF multimers are then packed into storage organelles within the cell (Weibel-Palade bodies). After which, the propeptide is cleaved and released. vWF circulates as multimers of disulfide linked 220kD subunits and the molecular weight of these multimers ranges from 0.5-20 million daltons. The plasma concentration of vWF is typically 10ug/ml. Increased levels are often observed in pregnancy and other conditions of physiological stress. von Willebrand’s Disease (vWD) is perhaps the most common inherited bleeding disorder in humans. It is the result of either quantitative deficiencies of vWF (vWD Types I & III), or one of a number of qualitative disorders of vWF structure and function (vWD Type II).

Capture Antibody (purified goat anti-human VWF IgG) 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. Plasma or other fluids containing vWF are applied. The coated antibody will capture the vWF in the sample. After washing, the plate to remove unbound material. Detection Antibody (purified goat anti-human VWF labeled with HRP) is added to the plate to bind to the captured vWF. After washing the plate to remove unbound labeled 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. The color produced is quantified using a microplate reader. The color generated is proportional to the concentration of vWF present in the sample.

Antibodies for 5x96 well plates V2700-09A: Capture Antibody: 1 x 500ul (Yellow capped tube). Purified goat anti-human VWF IgG. Suitable for use to coat ELISA plates. V2700-09B: Detection Antibody: 1 x 500ul (Red capped tube). Purified goat anti-human VWF labeled with HRP. Suitable for use in the detection of captured VWF.

May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. 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.