Factor VIII Activity

Test Code: TD_1470
CPT Code(s): 85240

$44

Test Details

Alternative Name(s)

Coagulation Factor 8 Activity
Factor 8 Activity
Factor 8 assay

Test Includes

Factor VIII Activity

Methodology

Electromechanical clot detection

Rejection Criteria

Hemolysis
Clotted samples
Room temperature samples
Refrigerated samples

Reference Range(s)

56-191%

Specimen Requirements

Preferred Specimen

Citrate (light blue top) tube

Minimum Volume

1 mL frozen plasma

Sample Stability

Unacceptable room temperature
Unacceptable refrigerated
1 month frozen

Transport Temperature

Critical Frozen

Collection Instructions

1. Fill a light blue top tube as far as vacuum will allow and mix by gentle inversion five to six times. The exact ratio of 1 part sodium citrate to 9 parts blood must be maintained. Inadequate filling of the sample tube will alter this ratio and may lead to inaccurate results.
2. Patients WHO have hematocrit values above 55% should have the anticoagulant adjusted to maintain the 1 to 9 ratio. For further instructions on the collection of platelet-poor plasma for patients with hematocrit value of >55%, please contact CPL Austin customer service.
3. To obtain platelet-poor plasma, immediately centrifuge sample at 1500 RCFs for 15 minutes, then pipette the supernatant plasma and transfer to a plastic transport tube.
4. Re-centrifuge plasma in the plastic transport tube at 15oo RCFs for 15 minutes to ensure that no red cells are present.
5. Pipette the top two-thirds of the supernatant plasma and transfer to another plastic transport tube. Clearly label tube as citrate plasma.
6. Immediately freeze the plasma at -20 degrees C or lower for transport. Critical Frozen (CFZ).
When multiple tests are ordered, submit separate tube for this test.
Patient prep: Patients should discontinue oral anticoagulant therapy for at least 2 weeks prior to testing, upon the advice of their physician.

Alternative Specimen

N/A