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Test Code 3153 von Willebrand Factor Antigen, Plasma

Performing Laboratory

Barnes-Jewish Hospital Laboratory

Methodology

Immunoturbidimetric Assay

Literature References:

HemosIL von Willebrand Factor Antigen package insert issued 02/2010, Instrumentation Laboratory.

Specimen Requirements

Specimen Type: Plasma

Container/Tube: Light-blue top (citrate)

Specimen Volume: 1 Full tube

Specimen Minimum Volume: Full tube

Collection Instructions:

1. Draw a discard tube prior to light-blue top (citrate) tube.

2. Tube should remain stoppered.

3. Do not centrifuge.

4. Clotted blood or an insufficient specimen is not acceptable.

5. Avoid hemolysis and heparin contamination of specimen.

Analyte Stability:

4 hours at 18° C to 24° C if the top has not been removed.
2 hours at 18° C to 24° C after the top has been removed.
Platelet-free plasma can be stored  6 months at -70° C.
Additional Information: If the patient is a hospital patient and the hematocrit is >55%, call Barnes-Jewish Hematology Laboratory at 314-362-5203 for instructions.

Day(s) Test Set Up

Monday, Thursday

Cut-off time: 0700

Turnaround Time:

STAT: not available

Routine: results available the day of testing

Reference Values

50%-200%

Literature References:

1. Sukhu K, Martin PG, Cross L, Keeling DM, Giangrande PL. Evaluation of the von Willebrand factor antigen assay using an immuno-turbidimetric method automated on the MDA 180 coagulometer. Clin Lab Haematol 2000;22(1):29-32.

2. Sadler JE. A revised classification of von Willebrand disease. Thrombosis and haemostatis. FK Schattauer Verlagsgesellschaft mbH (Stuttgart), 1994;71;520-5.

Test Classification and CPT Coding

85246

Additional Information

For BJH Laboratory Use Only

Analyte Stability:

4 hours at 18° C to 24° C if the top has not been removed.
2 hours at 18° C to 24° C after the top has been removed.
Platelet-free plasma can be stored 6 months at -70° C.

Laboratory Processing Instructions:
Test performed in BJH Hematology.

Specimen Transport Temperature

Ambient/Refrigerate NO/Frozen Yes

Ambient Whole Blood:  4 hours at 18° C to 24° C

Frozen Platelet-Free Plasma: 6 months at -70° C