vWF - von Willebrand Factor Deficient or Depleted Plasma

vWF – von Willebrand Factor Deficient or Depleted Plasma

Affinity’s vWF – von Willebrand Factor Deficient or Depleted Plasma is manufactured from pooled normal human plasma depleted of von Willebrand Factor using antibodies directed to vWF. Only the highest quality citrated plasma is used as starting material. Our Frozen Deficient or Depleted Plasma products are typically buffered with the addition of HEPES to 20mM final concentration and our Lyophilized Deficient Plasma products are typically buffered with the addition of HEPES to 50mM final concentration.

All vWF – von Willebrand Factor Deficient or Depleted Plasma from Affinity Biologicals are for Research Use Only and must not be used for diagnostic applications.

vWF – von Willebrand Factor Deficient Plasma

vWF – von Willebrand Factor Deficient Plasma is manufactured from normal citrated human plasma that has been depleted of vWF – von Willebrand Factor Deficient Plasma by selective affinity immuno-adsorption using antibodies directed towards vWF. Available in two different formats – Frozen and Lyophilized

Only the highest quality citrated plasma is used as starting material and in many cases the parent plasma is available as control material. Our vWF – von Willebrand Factor Deficient Plasma can be used for further manufacturing or research use only applications.

Frozen vWF Deficient Plasma

Product Code: VWF-DP

Presentation: Frozen vWF – von Willebrand Factor Deficient

Preparation/Handling: Thaw 1 ml vials in 37^oC water bath for 5 minutes; for bulk volumes, thawing time will be dependent on bottle size.

Storage and Stability: Plasma is shipped frozen and should be stored below -60^oC. Product is stable until date stated on vial label when stored at -60^oC. Once thawed, plasma is stable for 4 hours at 2-8^oC in original vial.

Certificate of Analysis: available upon request

Lyophilized vWF Deficient Plasma

Product Code: VWF-LDP

Presentation: Freeze Dried vWF – von Willebrand Factor Deficient containing 50 mM HEPES and stabilizers.

Reconstitution: Reconstitute with 1 mL of reagent grade water. Allow contents to dissolve for 15 minutes at room temperature with occasional swirling. Stability after reconstitution is 4 hours at ambient (18-25^oC), or 30 days at –20^oC.

Storage and Stability: Prior to reconstitution, dried plasma should be stored at 2-8°C. Product is stable until date stated on vial label when stored at 2-8^oC. Stability after reconstitution is 4 hours at ambient (18-25^oC), or 30 days at –20^oC.

Certificate of Analysis: available upon request

Description of von Willebrand Factor (vWF)

von Willebrand Factor (vWF, also 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 (antihemophilic factor) for secretion and transport in plasma. The vWF precursor protein is synthesized with a 95,000 dalton propeptide (also known as vWF antigen-II), 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 disulphide linked 220,000 dalton subunits and the molecular weight of these multimers ranges from 0.5-20 million daltons.

The plasma concentration of vWF is typically 10 μg/ml, but 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 and 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).

References and Reviews

Montgomery RR, Coller BS, in Hemostasis and Thrombosis, 3rd Edition, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp. 134-168, J.B. Lippincott Co., Philadelphia PA,.USA, 1994.
Sadler JE; von Willebrand Factor (Minireview); JBC 266:34, pp 22777-22780, 1991.