Veripath Test Directory

Synonyms Factor IX; Factor IX Assay; Antihemophilic Factor B; Christmas Factor.
Description Factor IX is a single chain vitamin K-dependent glycoprotein which is synthesized in the liver. Congenital deficiency of factor IX leads to Hemophilia B (or Christmas disease), which is an inherited disorder that causes mild to severe bleeding. Factor IX activity in a patient's plasma is determined by performing a modified activated partial thromboplastin time test (aPTT).
Specimen Requirements 
Container 3 mL Light blue (3.2% sodium citrate) collection tube
Specimen Type Blood
Preferred Collection Volume 3 mL
Minimum Collection Volume Adult: 2 mL, Neonates : 2 mL
Collection Instructions When drawing specimens for coagulation testing, always draw a "pilot" tube (7-10ml plain red top tube), completely filled. This removes tissue fluid contamination. Samples should be obtained from peripheral vein whenever possible. If drawn from indwelling catheter, the line should be flushed with 15mL of saline. After irrigation, a "pilot" tube should be drawn and discarded.
Specimen Handling In-house patients, transport at room temperature.
Out-side client, follow collection instructions and the steps below:
1. Spin light blue top tube. Remove plasma avoiding platelet/buffy coat layer. Spin plasma again to remove top portion of plasma ans place 1mL of PLATELET-POOR PLASMA in plastic tube. (Glass tube unacceptable). Double-centrifugation is critical for accurate results as platelet contamination may cause erroneous results.
2. Plasma must be frozen within 4 hours of collection. CRITICAL WARNING: Specimens must remain frozen until ready to test. Submit separate aliquots when multiple tests are ordered on the same patient specimen.
Rejection Criteria Hemolysis, clotted, short sample, >4 hrs old (if not frozen), thawed plasma, heparin contamination.
Methodology Clotting based assay
Reference Range 59 - 122%
CPT Code(s) 85250
Department Hemostasis/Coagulation
Contact Information Hemostasis Lab; 214-633-4959 Customer Service: 214-633-0400, Toll Free 1-877-887-8136.
Turn Around Time1 day
Performed Sunday - Saturday
Performed by Hemostasis Lab
Notes Results may be affected by Coumadin. Patient should be off Coumadin for at least 2 weeks.
Updated/Reviewed 07/25/2016