von Willebrand factor collagen binding activity (VWF:CB)
The VWF collagen binding assays (VWF:CB) assay is performed with an indirect ELISA. VWF in patient plasma is captured in microtitre plates coated with type III human collagen. Unbound material is then washed away and a solution of antibody to human VWF that is conjugated to an enzyme is added to ‘tag’ onto any captured VWF. Unbound conjugate is washed off and a substrate for the enzyme is added, the product of the enzyme-substrate reaction being coloured. Colour intensity is in direct proportion to the degree of conjugate-binding, itself proportional to the amount of VWF capture and thus, VWF collagen binding activity.
von Willebrand disease (VWD) is the most common hereditary bleeding disorder and the deficiency can be quantitative, involving reduced levels of normally functioning VWF, or qualitative, involving dysfunctional molecules. Laboratory investigation of VWD encompasses a battery of assays that assess different aspects of the molecule which inform sub-classification and clinical management:
VWF:RCo assay measures glycoprotein Ib binding
VWF:Ag assay measures total protein concentration irrespective of function
VWF:CB assay measures collagen binding
VWF:FVIIIB assay measures FVIII binding
Multimer analysis investigates VWF structure
FVIII activity is measured as levels can be reduced due to reduction of its carrier.
Blood group O 42 - 124
Non-O blood groups 59 - 147
400µL x 1 aliquot
Internal requests: please refer to EPR label
The sample should be analysed or manipulated & stored in the laboratory within 4 hours of venepuncture. Please ensure sample tubes are filled exactly to the fill-line as underfilling creates a dilution error and leads to inaccurate results.
North Wing - 4th and 5th Floors
Westminster Bridge Road
London SE1 7EH
Laboratory opening times
Last updated: 09/03/2017