Home


VWF
RISTOCETIN COFACTOR, PLASMA

Test Code VWF 
Test RISTOCETIN COFACTOR, PLASMA 
Methodology Platelet Agglutination 
Description Useful for diagnosis of von Willebrand's disease when used in conjunction with "Factor VIII Assay", "Von Willebrand Factor Antigen", and "Platelet Aggregation With Ristocetin" assay. 
Specimen Collect specimen as follows:
1. Draw blood in light blue-top (3.2% sodium citrate) tube(s). Separate plasma from cells within 1 hour of collection in a centrifuge at 2,500 rpm for 15 minutes or 3,000 rpm for 10 minutes.
2. Using a plastic transfer pipette (do not use a glass pipette) decant the plasma to a screw-capped, plastic (polypropylene) vial. (Glass vials will not be accepted.)
3. Divide the specimen into as many 0.5 - 1.0 mL aliquots as possible and cap the vial(s) tightly.
4. Freeze specimen(s) immediately at <= -40 C.
5. Send specimen(s) FROZEN on dry ice.

NOTE:
1. SPECIMENS WILL BE REJECTED IF UNDERFILLED (< 90%), CLOTTED, HIGH HEMATOCRIT (> 55%), OR GROSSLY HEMOLYZED.
2. Follow "Special Procedure for Drawing Specimen from an A-line". 

Reference Values 50 - 150% 
Analytic Time 1 Day 
Day(s) Test Set Up Monday and Friday only 
CPT Code(s) 85245  

Special Instructions