Ristocetin Cofactor

Centralized Core Laboratory:Hematology

Test ID/Workstation: RISCO ACOAG

Specimen Type: Blood

Tube Type: Blue top (sodium citrate) tube

Collection Volume: 2.7 mL (minimum 1.8 mL)

Cause for rejection: Specimens which have visible hemolysis, are clotted, collected in wrong tube, diluted with IV fluids, contaminated with heparin, tubes that are over or under filled, specimens not kept on ice, or specimens received more than one hour post collection.

Storage: Frozen

Availability: Daily, 0700-1500

Methodology: Chromogenic Assay

Special Instructions: Specimens should be spun down & platelet poor plasma frozen if coming from an off site facility (plasma volume minimum 0.5 mL)

If collected at an offsite location, send by a STAT Courier to Hospital lab.

Lab/Phone: 330-543-8418

TAT: 4 hours

Additional Info: Reference range: 50-150%

CPT Code: 85245

Synonyms: von Willebrand Factor Activity

Requisition Form
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