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HelpTest Code F-VIII Factor Assay-8 (VIII)
Synonyms/Keywords
Factor VIII Activity, AHF, FVIII
Specimen Requirements
| Specimen Type | Preferred Container/Tube | Acceptable Container/Tube | Specimen Volume | Specimen Minimum Volume (allows for 1 repeat) |
Pediatric Minimum Volume (no repeat) |
|---|---|---|---|---|---|
| *Platelet Poor Plasma | 3.2% Citrated Blue Top Tube (BTT), Citrated Blue Top Tube (BTT) | 0.75 mL | 0.75 mL | 0.5 mL |
Collection/Processing Instructions
One 0.75 mL citrated Blue Top Tube (BTT) plasma aliquot. (If more than one coagulation test is ordered, a separate aliquot is needed for each test.)
- Collect in Citrated Blue Top Tube (BTT)
- Citrate anticoagulant must be adjusted for HCT >55%
- Tube must be at least 90% full
- Invert completely 3-4 times (without shaking) to mix
*See Instructions for: Preparation of Platelet Poor Plasma
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma | Frozen | 6 months |
Rejection Criteria
| Clotted or Hemolyzed |
|---|
| Contamination with IV or Hickman Line fluid |
| Specimens that thaw during storage or transport |
Reference Range Information
| Performing Location | Reference Range |
|---|---|
| Marshfield | <1 year of age: No reference range established for this age range >1 year: 60-135% of normal activity |
Marshfield Labs Performing Department
Marshfield Labs Hematology
Performing Information
| Performing Location | Day(s) Test Performed | Analytical Time | Methodology/Instrumentation |
|---|---|---|---|
| Marshfield | Monday and Thursday | Less than 2 hours | Siemens CS2500 |
CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 85240 |
Outreach CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 85240 |
Ordering Applications
| Ordering Application | Description |
|---|---|
| Centricity | Factor-VIII |
| Cerner | Factor VIII Assay |
| COM | Factor Assay-8 (VIII) |