Sign in →

Test Code 3753 von Willebrand Activity

Performing Laboratory

Barnes-Jewish Hospital Laboratory

Methodology

Immunoturbidimetric Assay

Reflex Information              

If  result is abnormal, # Ristocetin cofactor activity will be performed at an additional charge

Literature References:      

HemosIL von Willebrand Factor Activity package insert issued 04/2010, Instrumentation Laboratory.

                                  

Specimen Requirements

Specimen Requirement (Tube/Container)      

Specimen Type: Plasma

Container/Tube: Light-blue top (citrate)

Specimen Volume: 1 Full tube

Specimen Minimum Volume: 1 full tube

Collection Instructions:

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

2. Tubes 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.

6. Blood should not be drawn through an indwelling catheter or an A-V shunt.

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

55-189 %     

    

Literature References:

Raneem O. Salem, Elizabeth M. Van Cott, A New Automated Screening Assay for the Diagnosis of von Willebrand Disease, Am J Clin Pathology 2007; 127:730-735                                           

Test Classification and CPT Coding

85245

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

Barnes-Jewish Hospital Additional Information:

Laboratory Processing Instructions        

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.