Laboratory Test Directory

FACTOR IX ASSAY: (089-0007)

Clinical Indication:

 Measures levels of factor(s) that can be useful in diagnosing bleeding disorders and liver disease.

Test Mnemonic:

 FACTORIX

Methodology:

 Electromagnetic Viscosity Detection

Performed:

 Samples are accepted 24 hours per day at Sample Management, 5.136 McCullough Bldg.

Turnaround Time:

 STAT: 1  hour; ROUTINE: 4 hours

Specimen Requirements:

Patient Preparation: Patient must not be on any anticoagulation therapy for 48 hours before blood collection.

Collect: Blue-topped (3.2% sodium-citrate) tube. Routine venipuncture; discard 1st mL of blood by collecting a discard tube prior to collecting the blue-topped (3.2% sodium-citrate) tube.  For collections with butterfly blood collection sets, a discard tube should also be collected prior to collection of the blue top to ensure sufficient sample volume. Drawing a discard tube will displace the air from the blood collection set tubing to ensure proper blood draw volume.

Specimen Preparation: Samples should be received in laboratory within ½ hour of draw for best results.  Acceptable up to 4 hours after draw, at ROOM TEMPERATURE.

Storage/Transport:  NOTE: If delivery time is to be greater than 4 hours from time of draw, centrifuge the sample for 15 minutes at 2000-2500g to ensure platelet poor plasma.

·         Transfer plasma to 12x75 plastic tube

·         Cap tube and re-spin for 15 minutes at 2000-2500g

·         CAREFULLY remove from centrifuge without disturbing any platelets and/or cell pellets that might be on the bottom or sides of the tube.

·         Carefully transfer plasma into freezer tubes (plastic screw-top cryo-tubes) for testing or freezing.

 Stability: Plasma 4 hours at 20+/- 5°C. Frozen Plasma 15 days at -20°C.  Frozen plasma 1 month at -80°C.   .

Causes for Rejection: QNS, clotted, severely hemolyzed specimen, specimen greater than 4 hours old, wrong tube (3.8% sodium citrate), high hematocrit (> 55%), sample identification error, sample processed/transported, and/or stored improperly.

Clinical Information:

Interfering substances:  oral contraceptives, anticoagulant therapy, thrombin inhibitors. The presence of lupus anticoagulants may lead to an under-estimation of the FIX level.

Reference Range:

0.76 - 1.58 Units

Note:

CPT 4 Code:

 85250

 Reviewed: 3/20/13

W.Russo, MT(ASCP)

When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient.  Components of the organ or disease panels may be ordered individually.  The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-9 code or its verbal equivalent.