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Test ID: VWFM2    
von Willebrand Factor Multimer Analysis, Plasma

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Specimen Type Describes the specimen type needed for testing

Plasma Na Cit

Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.

VWFX / von Willebrand Factor Activity, Plasma and VWAG / von Willebrand Factor Antigen, Plasma are required before performing this test. If already assayed, submit results. If no results are included, submit separate specimens for the above assays following specimen requirements for each test. 

 

See Coagulation Studies in Special Instructions.

 

Specimen Type: Platelet-poor plasma

Collection Container/Tube: Light-blue top (citrate)

Submission Container/Tube: Plastic vials

Specimen Volume: 1 mL in 2 plastic vials each containing 0.5 mL

Collection Instructions:

1. Specimen should be drawn prior to coagulation factor replacement therapy.

2. Spin down, remove plasma, and spin plasma again.

3. Freeze specimens immediately at < or =-40 degrees C, if possible.

4. Send specimens in the same shipping container.

Additional Information:

1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

2. Each coagulation assay requested should have its own vial.

3. Coagulation testing is highly complex, often requiring the performance of multiple assays and correlation with clinical information. For that reason, we suggest ordering VWPR / von Willebrand Profile.

Forms: Coagulation Patient Information Sheet (Supply T675) in Special Instructions

Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.

0.5 mL if prior ristocetin cofactor or von Willebrand factor activity and von Willebrand factor antigen results are provided, otherwise 1 mL is required.

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

Hemolysis

Mild OK; Gross reject

Lipemia

Mild OK; Gross reject

Icterus

Mild OK; Gross reject

Other

NA

 

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.

Specimen TypeTemperatureTime
Plasma Na CitFrozen42 days