von Willebrand factor activity


vWF activity (ristocetin cofactor)

Also known as

ristocetin cofactor, von Willebrand, RiCoF

Request a test

To request this test please send sample with a request providing patient ID (three identifiers), specimen information, assay required, relevant clinical details and sender information. Before sending sample please read details on requesting and labelling by clicking on the link. Please also refer to any additional information provided for this test. Download the referral form >

Additional information

Fill exactly to the line indicated on the bottle. Sample must arrive within I hour of collection and before 4pm. Capillary samples are unsuitable for coagulation tests. If the test is required as part of von Willebrand investigations, no additional sample is required A full set of von Willebrand investigations requires 4 x 1.4ml samples. Please state the reason for the request in the clinical details.

Sending address

Department of Haematology Camelia Botnar Laboratories Great Ormond Street Hospital Great Ormond Street WC1N 3JH

Laboratory service


Sample requirements

1.4ml venous blood, citrate

Reference range

Please click on the link to view reference range View the reference range for this test >

Turnaround time

30 days


Upon request

Call in advance?

Not required


The Haematology Department provides a wide range of specialist tests with a special interest in the diagnosis and monitoring of coagulation disorders.

© 2011 Great Ormond Street Hospital for Children NHS Trust