ARUP's Laboratory Test Directory

von Willebrand Factor Activity (Ristocetin Cofactor) : 0030250

Mnemonic: RCF

Methodology: Platelet Agglutination
Performed: Mon-Sat
Reported: 1-3 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: 51-215%
7-9 years: 52-176%
10-11 years: 60-195% 
12-13 years: 50-184%
14-15 years: 50-203 %
16-17 years: 49-204%
18 years and older: 51-215%
CPT Code(s): 85245
 
 

 

 

 
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