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Explore a solution that sets a new standard in von Willebrand factor activity determination.

The INNOVANCE® VWF Ac assay is a sensitive, reliable, and convenient test system for direct, WHO-standardized determination of von Willebrand factor (VWF) activity. It is used as an aid in the diagnosis and monitoring of congenital or acquired VWF deficiencies in patients with bleeding disorders or at risk for VWF deficiency. In addition, it can be used for monitoring VWF substitution therapy. It employs an advanced new technology, allowing the assay to mimic the way in which VWF binds to glycoprotein Ib (GPIb), the major VWF receptor protein on platelets. Because the recombinant receptor protein includes two gain-of-function mutations, the assay does not require ristocetin.

Features & Benefits


Utilizes recommended screening method

A functional assay is the preferred screening method for detecting quantitative as well as qualitative defects of von Willebrand factor.1


Direct determination of VWF activity

The INNOVANCE VWF Ac assay directly determines activity of VWF. Due to the gain-of-function mutations, VWF binding to GPIb does not require ristocetin (VWF:GPIbM)2 and is therefore less susceptible to effects of certain polymorphism variants.


Excellent correlation to the gold-standard method

The INNOVANCE VWF Ac assay shows excellent correlation with the ristocetin cofactor-based BC von Willebrand assay. 


Improved VWF testing workflow

The assay employs a liquid, ready-to-use reagent that requires no stirring.

Prof. Steven Pipe, MD

Technical Specifications

16 μL
Required sample volume on Sysmex® CS-2500 and CS-5100 Systems

4–300% of norm
Measuring range

24/72 hours
Onboard stability on Sysmex CS-2500 and CS-5100 Systems

36 hours
Onboard stability on BCS®  XP System

Within-device CV Control Plasma N on System CS-2500 and CS-5100 Systems

~110 tests
Number of tests per kit on Sysmex CS-2500 and CS-5100 Systems

The INNOVANCE VWF Ac assay is a turbidimetric, latex-based assay that employs a liquid, ready-to-use reagent. The assay consists of three components and can be ordered as a kit.

Reagent III

Reagent II

Reagent I

INNOVANCE VWF Ac assay kit

  1. Siemens Healthineers INNOVANCE VWF Ac reagent I

    Description: Buffer with polystyrene particles coated with anti-GPIb monoclonal antibodies

BCS XP System

Available on BCS XP System

INNOVANCE VWF Ac assay applications are available on BCS® XP Systems from Siemens Healthineers and Sysmex CS-2500 and CS-5100 Systems. 

Clinical Use

Von Willebrand Disease Algorithm

Diagnostic algorithm for patients suspected of VWD1

To correctly diagnose cases involving a bleeding anamnesis or a family history of von Willebrand disease and subsequently monitor patient response to therapy, physicians require a specific test for von Willebrand factor. A functional assay is the preferred screening method for detecting quantitative as well as qualitative defects of von Willebrand factor. For more details on VWD subtypes and management, recommended lab diagnostics, and the benefits of the INNOVANCE VWF Ac assay, download the brochure.

Photo of vWF Ag assay from Siemens Healthineers

vWF Ag assay3 from Siemens Healthineers

For the evaluation of von Willebrand disease, VWF activity assays can be combined with VWF antigen assays to detect and distinguish between quantitative and qualitative VWF deficiencies.1  

The vWF Ag assay3 is an immunoturbidimetric assay that can be used on all Siemens Healthineers and Sysmex automated coagulation instruments. 

Upgrade your bleeding diagnostics with a comprehensive portfolio of systems and assays

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