Ordering Recommendation

Order to diagnose factor IX deficiency, detect factor IX inhibitors, and monitor factor IX replacement therapy.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Lt. blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.

Specimen Preparation

Transfer two 3 mL aliquots of platelet-poor plasma to two ARUP Standard Transport Tubes. (Min: 2 mL/each)

Storage/Transport Temperature

CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions

Serum. EDTA plasma, clotted or hemolyzed specimens.


Ambient: 4 hours; Refrigerated: Unacceptable; Frozen: 2 weeks


Electromagnetic Mechanical Clot Detection




1-3 days

Reference Interval

Test Number
Reference Interval
  Factor IX, Activity
Age Reference Interval (%)
1-4 days 15-91
5-29 days 15-91
30-89 days 21-81
90-179 days 21-113
180-364 days 36-136
1-5 years 47-104
6 years 63-89
7-9 years 70-133
10-11 years 72-149
12-13 years 73-152
14-15 years 80-161
16-17 years 86-176
18 years and older 78-184

  Bethesda Quantitative, F9 0.4 BU or less

Interpretive Data

Compliance Category



If Factor IX activity is 20 percent or less, then Bethesda Quantitative, Factor IX will be added. Additional charges apply.

Hotline History


CPT Codes

85250; if reflexed, add 85335


Component Test Code* Component Chart Name LOINC
0030033 Bethesda Quantitative, F9 3185-6
0030100 Factor IX, Activity 3187-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Bethesda Quantitative Factor IX
  • Coagulation Factor IX Inhibitor, Plasma
  • Factor IX Inhibitor Concentration
  • Factor IX Inhibitor, Quantitative
  • Factor IX, Activity
Factor IX Activity with Reflex to Bethesda Quantitative, Factor IX