Factor VIII Activity, Chromogenic

Test Code
16049

CPT Codes
85240

Preferred Specimen
1 mL  plasma collected in 3.2% sodium citrate (light-blue top) tube

Minimum Volume
0.5 mL

Instructions
Platelet-poor plasma: Centrifuge light blue-top tube 15 minutes at approx. 1500 x g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/mcL).
Freeze immediately and ship on dry ice.

Note: Storage of whole blood at refrigerated temperatures prior to processing may lead to cryoprecipitate formation and falsely low Factor VIII.

Transport Temperature
Frozen

Specimen Stability
Room temperature: 8 hours
Refrigerated: 8 hours
Frozen: 21 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Received room temperature • Received refrigerated • Received thawed • Hemolysis

Methodology
Chromogenic Assay

Setup Schedule
Set up: Wed, Sat a.m.; Report available: 2-6 days

Reference Range
50-160 % normal

Clinical Significance
Preferred test in patients with Lupus anticoagulant, on heparin or direct thrombin inhibitors, or on Factor VIII concentrates.

Performing Laboratory
Quest Diagnostics Nichols Inst San Juan Capistrano
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130



The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.