Test directory: Ristocetin Cofactor

Ordering Code 573
Test Name Ristocetin Cofactor
Alias RcoF
Von Willebrand Factor Ag Activity
Preferred Specimen Plasma
Preferred Container Citrate, 3.2% (Lt Blue)
Optimum Volume 1 mL
Collection Instructions Fasting specimen preferred, but not required
Draw full tube.
Handling Instructions Double centrifuge plasma within 60 minutes of collection
Separate and freeze immediately
Strict frozen. Do not thaw.
Transport Requirements Oahu: Frozen
Airline: Frozen
Specimen Stability Ambient: 6 Hours
Frozen: 3 Weeks
Rejection Criteria Ambient, Refrigerated, Hemolyzed, Lipemic, Thawed
Avail. Stat NO
Analytic Time Up to 8 Days
Methodology Platelet Agglutination
Reference Lab  Quest Diagnostic Lab-NI

Reference range(s)

The reference ranges listed below are valid on this date of June 29, 2025.
Component Age Male Norm Male Critical Low Male Critical High Female Norm Female Critical High Female Critical Low Units Add'l info
Ristocetin Cofactor ALL See report.