Ristocetin cofactor assay

This is an important test that can be used to investigate the cause of bleeding events and to diagnose VWD.

Venous blood
1 tests included
7 days turnaround



About Ristocetin cofactor assay

What is ristocetin cofactor?

Ristocetin cofactor, also known as the von Willebrand factor (vWF), is a coagulant factor the helps the blood to clot. vWF causes platelets to clump together at an injury site. Platelets are cells that help to form plugs and stop bleeding.

vWF must function properly to prevent excessive bleeding. von Willebrand disease (VWD) is a bleeding disorder that occurs if there is a lack of vWF or if it does not function normally. This condition is caused by a genetic change which can be inherited.  

Why take this test?

This test measures the activity of vWF which is required for clotting. This test can be used to investigate the cause of bleeding events and to diagnose VWD.


What's tested

Ristocetin Co Factor Assay

How it works



Purchase your Kit

Just order a test online and get your kit delivered right to your door unless you are ordering a COVID-19 Fit to Fly test where you will be given appointment options to attend our clinics across the United Kingdom for a nose and throat swab PCR test at the checkout stage.



Take your test and post

Follow our simple instructions to take your sample and post back the enclosed prepaid envelope to our accredited lab for processing. We also offer home or workplace visits by a qualified nurse. For COVID-19 Fit to Fly tests you must attend one of our partner clinics for our trained collection officers to take your sample. You will then have the results emailed to you.



Get results directly to your dashboard

You will receive an email notification from our medical team when your results are available on your secure personalised health dashboard.