Factor VIII Antigen
Also known as: FVIII Quantitation (Nonfunctional)
Use
Quantitate the amount of factor VIII protein; not a measure of von Willebrand factor antigen (previously called FVIII-related antigen)
Special Instructions
The test is performed using an enzyme-linked immunosorbent assay (ELISA). It's important to ensure proper sample collection and handling procedures to maintain sample integrity. Double centrifugation is required to prepare citrated plasma, and it must be frozen immediately after preparation.
Limitations
The test specifically measures the concentration of factor VIII protein. It does not assess the functionality of factor VIII or the presence of von Willebrand factor antigen. Incorrect sample collection, handling, or storage may impact results. The reference range might vary based on patient age and should be interpreted within clinical context.
Methodology
Immunoassay (ELISA)
Biomarkers
LOINC Codes
- 38521-1
Result Turnaround Time
3-7 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
2 mL
Minimum Volume
1 mL
Container
Blue-top (sodium citrate) tube
Collection Instructions
Citrated plasma samples should be collected by double centrifugation. Use a blue-top tube containing 3.2% buffered sodium citrate. Mix the sample immediately by gentle inversion at least six times. A discard tube is needed when using a winged blood collection device. After collecting non-citrate tubes, collect the citrate tubes. Centrifuge and carefully remove plasma without disturbing cells. Transfer to a plastic tube, recentrifuge and transfer plasma, staying clear of platelets.
Storage Instructions
Freeze immediately and maintain frozen until tested.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Stable for four hours |
| Refrigerated | Stable for eight hours |
| Frozen | Three freeze/thaw cycles are acceptable |