Test Code RCF Ristocetin Cofactor
Laboratory Code
LAB335
Specimen Requirements
Submit only one of the following specimens
Specimen Type: Whole Blood
Container/Tube: 2 Light Blue Top (3.2% Sodium Citrate)
Volume: 2 × 2.7 mL (Tubes must be full)
Collection Instructions: Send whole blood specimens to laboratory immediately.
Specimen Type: Platelet Poor Plasma
Container/Tube: 2 Light Blue Top (3.2% Sodium Citrate)
Submission Container/Tube: Plastic Vial
Minimum Volume: 1.0 mL plasma
Collection Instructions:
1. Light blue top tube must be properly filled with whole blood.
2. Whole blood specimen should be double centrifuged and plasma separated from cells within 1 hr of collection.
3. Plasma should be separated into 2 aliquots with minimum volume of 1.0 mL each.
4. Freeze the aliquots in well-closed plastic tubes immediately.
Specimen Stability
Specimen Type | Plasma |
---|---|
Ambient | 4 hours |
Refrigerate | 4 hours |
Frozen | 14 days (preferred) |
Methodology
Immunoturbidimetric Assay
Days and Times Performed
Friday, TAT 21 days
Specimen Condition
Haemolysis | Gross reject |
---|---|
Icterus | Gross reject |
Lipaemia | Gross reject |
Others: Clotted or insufficient | Reject |
Reference Interval
Blood O-group | 44 – 141 % |
---|---|
Blood group non-O | 63 – 200% |
Testing Laboratory
National University Hospital
Haematology, 67725320
Useful For
Aids in the diagnosis of von Willebrand’s Disease.
Service Code
12021
Alias
Ristocetin Cofactor Activity
RCF
Ricof
Ristocetin
vWF Activity
von WIllebrand’s Disease
vWD
Update
Last updated 21/03/2025