Routine: 1 Day
Urgent: N/A

Batched daily 7 days per week. Please call 503-494-5764 if STAT.

3.2% sodium citrate tubes are acceptable when they are filed to the line on the manufacturers label. Tubes must be full (see comments below). For referral testing, submit 2 x 1.0 mL frozen platelet poor citrated plasma.

Sodium citrate specimens must be processed and frozen within 2 hours of specimen collection.

OHSU clinics must cab specimen to the Core Lab, Hatfield Research Center (HRC), Room 9D05 if processing is delayed or not possible on site. A phone call is helpful to alert the lab at 503-494-5764.

Detailed instructions are under Hemostasis & Thrombosis section (Opens in a new window).

Add blood to the 1.3 mL mark of Pediatric BLUE top tube, 3.2% sodium citrate. For pediatric patients requiring multiple coagulation tests, please call 503-494-7383 regarding draw volumes.

Reference Range: 65% to 150%

Draw volume is critical due to the liquid anticoagulant. Allow tubes to fill by vacuum.

• Tubes with rubber stopper: fill to line on label.
• Tubes with plastic (Hemogard) cap: the fill level is above the top of the label.
• Syringe: do not remove the vacutainer stopper. Insert the needle through the stopper and allow the tube to fill by vacuum. Do not overfill the vacutainer.
• Pediatric tubes have no vacuum. Remove the cap and add blood to the 1.3 mL mark. Do not overfill.

Avoid warfarin (Coumadin) therapy for 2 weeks and heparin therapy for 2 days prior to the test.

Assay to document Factor IX deficiency. Factor IX deficiency (PTC or plasma thromboplastin component or Christmas disease) is commonly referred to as hemophilia B. It has a recessive sex-linked mode of inheritance, males are affected, females are carriers. It occurs in 1 of 25,000 males. Low levels of factor IX may be present in patients with liver disease. Severity of the symptoms correlate directly with the degree of prolongation of APTT test (level of factor IX deficiency). Mildly affected patient may show excessive bleeding only with major trauma or surgery. The APTT may not be prolonged if the factor IX level is over 25%. In most cases of hemophilia B, the prothrombin time and thrombin times are normal. A subgroup of cross reacting material positive hemophilia B patients, however, is defined by its markedly prolonged ox-brain prothrombin time. The molecular defect of this "hemophilia Bm" (factor IXHilo) has recently been described. Methodology: APTT based clotting assay.

F9A
Factor IX
Factor 9