|Test||VON WILLEBRAND FACTOR ANTIGEN, PLASMA|
|Methodology||LATEX IMMUNO-TURBIDIMETRIC ASSAY (LIATEST)|
|Description||Useful for diagnosis of von Willebrand's disease when used in conjunction with "Factor VIII Assay", "Von Willebrand Factor Assay (Ristocetin CoFactor)", 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.
NOTE: Double-centrifuges specimens are critical for accurate results as platelet contamination may cause spurious results.
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.
|Reference Values||50 - 160%|
|Analytic Time||1 Day|
|Day(s) Test Set Up||Once weekly|