Test Catalog



Alternative Names: B191, Bethesda Quantitative Factor VIII, Inhibitor, Coagulation Factor VIII Inhibitor Panel, Plasma, Factor VIII Inhibitor Profile
Includes: Factor VIII, Activity, Bethesda Quantitative, F8
Sample Type: Citrated Platelet Poor Plasma (PPP), see below for instructions
Preferred Container: Sodium Citrate (Blue Top, 3.2%) Tube
Sample Volume: Two 3 mLs aliquots of platelet-poor plasma (Total: 6 mLs)
Handling Instructions: Transfer two 3 mL aliquots of platelet-poor plasma to Standard Transport Tubes. (Min: 2 mL/each)
CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.
Transport Temperature: Critical Frozen
Specimen Stability: Frozen at -20°C: 3 months; Frozen at -70°C: 6 months
Testing Frequency: Monday- Saturday
Expected Turn Around Time: 2-4 Days
Testing Facility: Ref Lab ARUP
CPT Codes: 85240; if reflexed, add 85335
Note: Specimen preparation for PPP:
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. To obtain platelet-poor plasma, immediately centrifuge sample at 1500 RCFs for 15 minutes, then pipette the supernatant plasma and transfer to a plastic tube.
3. Re-centrifuge plasma in the plastic transport tube at 1500 RCFs for 15 minutes to ensure that no red cells are present.
4. Pipette the top two-thirds of the supernatant plasma and transfer to another plastic transfer tube.
5. Immediately freeze the plasma at -20 degrees C or lower for transport. Critical Frozen.
6. When multiple tests are ordered, submit separate tube for this test.