ARUP's Laboratory Test Directory

0030250: von Willebrand Factor Activity (Ristocetin Cofactor)

Test Mnemonic: RCF
Methodology: Platelet Agglutination

Performed: Mon, Wed, Fri

Reported: 1-4 days

Specimen Required:  
Collect: One 5 mL lt. blue (sodium citrate).  Refer to the Hemostasis/Thrombosis Specimens section in the front of this User's Guide for specimen collection instructions.

Transport: 2 mL platelet-poor plasma, frozen. (Min: 1 mL) Submit specimen in an ARUP Standard Transport Tube.

Pediatric Collection/Transport: 1 mL platelet-poor plasma, frozen.

Remarks: CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions: Serum.  Nonfrozen or hemolyzed specimens.

Stability: Ambient: 4 hours; Refrigerated: 8 hours; Frozen: 2 weeks

Reference Interval:
0-6 years: 44-195 %
7-9 years: 51-172%
10-11 years: 61-195% 
12-13 years: 47-183%
14-15 years: 50-215 %
16-17 years: 47-206%
18 years and older: 44-195%

CPT Code(s):
85245

 

 

 
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