ARUP's Laboratory Test Directory

Factor VIII, Activity : 0030095

Mnemonic: F8

Ordering Recommendation: Order to diagnose hemophilia A, acquired factor VIII deficiency, or as part of a diagnostic workup for von Willebrand disease. Not recommended when screening for thrombophilia.
Methodology: Clotting
Performed: Mon-Sat
Reported: 1-3 days
Specimen Required: Collect: Lt. blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.

Specimen Preparation: Transfer 2 mL platelet-poor plasma to an ARUP Standard Transport Tube. (Min: 1 mL)

Storage/Transport Temperature: CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Remarks:

Unacceptable Conditions: Serum. Non-frozen or hemolyzed specimens.

Stability (collection to initiation of testing): Ambient: 4 hours; Refrigerated: Unacceptable; Frozen at -20° C: 3 months; Frozen at -70° C: 6 months
Reference Interval:
0-6 years: 56-191%
7-9 years: 76-199%
10-11 years: 80-209%
12-13 years: 72-198%
14-15 years: 69-237%
16-17 years: 63-221%
18 years and older: 56-191%
CPT Code(s): 85240
Cross References: AHF (Factor VIII, Activity), Antihemophilic Factor (AHF), Factor VIII:C (Coagulant Portion) (Factor VIII, Activity), Antihemophilic Factor (Factor VIII, Activity), Coagulation Factor VIII Activity Assay, Plasma (Factor VIII, Activity), Hemophilia A (Factor VIII, Activity), Intrinsic Factor Proteins (Factor VIII, Activity), Intrinsic Factors (Factor VIII, Activity)