Ristocetin Co-Factor
Test Mnemonic
RISCOF
CPT Codes
- 85245 - QTY (1)
Aliases
- Von Willebrand Factor Activity
Performing Laboratory
Cleveland Clinic Laboratories
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL | Plasma | Sodium citrate (Lt. Blue) | Frozen | Plasma must be frozen within 4 hours of collection. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | 4 hours |
| Refrigerated | Unacceptable |
| Frozen | 14 days at -20 C; 6 months at -70 C |
Days Performed
Mon - Fri
Turnaround Time
1 - 3 days
Methodology
| Name | Description |
|---|---|
| Aggregation |
Reference Range
| Ristocetin Co-Factor | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Years | 99 Years | Normal | 42-146 | % |
Special Info
3.2% sodium citrate is the preferred anticoagulant recommended by CLSI.
Clinical Info
To be used in the diagnosis of von Willebrand's Disease. For complete evaluation and classification of von Willebrand's disease, suggest ordering the VWF panel. The Ristocetin cofactor assay tests the functional activity of von Willebrand factor.