Chromogenic Factor VIII Activity ()
Department: Coagulation
Test Synonym(s): LAB6350, CHROM FVIII, Chromogenic F8 Activity
CPT Codes: 85240
Methodology: Chromogenic
Reference Range: 50-100 %
Tube Type: One 2.7 mL light blue top tube (sodium citrate)
Specimen: Citrated platelet poor plasma - Requires double centrifugation if sending a plasma aliquot. Aliquot(s) must be frozen if not received by lab within 4 hours of collection.
Alternate Specimen: None
Pediatric Requirements: Pediatric: One 2.7mL Light blue top - 3.2% Sodium Citrate. Neonatal: One 1.8mL Light blue top - 3.2% Sodium Citrate.
Volume: 1.0 mL
Minimum Volume: 1.0 mL
Temperature: Room Temperature for Light blue top tube, must be received within 4 hours of draw. Plasma aliquot(s) must be frozen if not received by lab within 4 hours of collection.
Stability: Room temperature: 4 hours, Frozen: -70 C for one month
Reasons for Rejection: Clotted sample, incorrectly filled tubes, incorrect tube type, grossly hemolyzed sample, grossly lipemic sample, grossly icteric sample, whole blood >4.0 hours old
Days Performed: Monday - Sunday
Times Performed: 8:00 AM - 3:00 PM Monday - Friday. 8:00 AM - 12:00 PM Saturday and Sunday. Tests requested after hours or on holidays have to be approved by the Medical Director.
TAT: 1 - 3 days
Significance: The Chromogenic Factor VIII activity assay is used to quantitate Factor VIII levels on patients receiving HemlibraŽ. The assay is not intended for the routine quantitation of Factor VIII levels. The appropriate test is F8, LAB306.
Special Instructions: The Chromogenic Factor VIII activy assay is used to quantitate Factor VIII levels on patients receiving HemlibraŽ. The assay is not intended for the routine quantiation of Factor VIII levels. The appropriate test is F8, LAB306. Indwelling line should be flushed with saline and 5.0 mL of blood discarded before collecting samples for coagulation assays. Tube must be full and not clotted. Deliver to lab immediately. Samples received from an outside lab must be aliquoted and frozen. Indwelling line should be flushed with saline and 5.0 mL of blood discarded before collection samples for coagulation assays. The tube must be full and not clotted. Deliver to lab immediately. Samples received from an outside lab must be aliquoted and frozen. Samples aliquoted for shipping must be double centrifuged prior to freezing. Grossly hemolyzed, icteric, or lipemic samples may be rejected.
Search Help
Search Options for the Test Directory:
1. Enter the test name in the Keyword search field.
Hint: You can also enter any part of the test name to expand the search.
(Example: you can type "west" or "sed" or "rate" to find Westergren Sedimentation Rate)
2. Enter the Vanderbilt Test Code, if known.
3. Choose one of the letter boxes to display a list of all test names and keywords starting with that letter.
If you are unable to find a test in our directory, please contact VPLS at
1-800-551-5227 or e-mail emily.k.thompson@vumc.org.