Ordering Guidance

For monitoring factor VIII infusions or diagnosing hemophilia, order F8A / Coagulation Factor VIII Activity Assay, Plasma.

Necessary Information

Specimen Required

Specimen Type: Platelet-poor plasma

Patient Preparation: For at least 12 hours before specimen collection, the patient should not be given infusions of factor VIII concentrates.

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vial (polypropylene preferred)

Specimen Volume: 1 mL Platelet-poor plasma

Collection Instructions:

1. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing

2. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.

3. Aliquot plasma into a plastic vial, leaving 0.25 mL in the bottom of centrifuged vial.

4. Immediately freeze plasma (no longer than 4 hours after collection) at -20° C or, ideally, at -40° C or below.

Additional Information:

1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

2. Each coagulation assay requested should have its own vial.