Lab Dept:


Test Name:

Prothrombin Fragment 1.2

General Information

Lab Order Codes:



PT 1.2

CPT Codes:

85397 – Coagulation and fibrinolysis, functional activity, not otherwise sepcified, each analyte

Test Includes:

Prothrombin fragment 1:2 reported in seconds.


Test Indications:

Useful for diagnosing hypercoagulable state and as a marker for DIC. Determines if a fragment of Prothrombin called F1.2 is present. This fragment is produced when the patient's coagulation system is activated.

Lab Testing Section:

Coagulation - Sendouts

Referred to:

Fairview University Medical Center (Fairview/Atlas test: PF)

Phone Numbers:

MIN Lab: 612-813-6280

STP Lab: 651-220-6550

Test Availability:

Daily, 24 hours

Turnaround Time:

Performed once/week; results are reported within 2 – 7 days.

Special Instructions:

A clean venipuncture is essential.


Specimen Type:

Whole blood


Light Blue top (Buffered Na Citrate 3.2 %) tube

Draw Volume:

2.7 mL blood in a 3 mL tube (Minimum: 1.8 mL in a 2 mL tube)

Processed Volume:

Specimens will be processed at reference lab facility if received within 3 hours of collection. Otherwise, specimens need to be processed at referring facility and provide minimum of two 0.5 mL specimens frozen at -70. Follow directions below under Special Processing.


Routine venipuncture or line draw. Do Not use the first 2 mL of blood collected.
If the patient’s hematocrit is >55%, contact laboratory to obtain a special tube.
Mix thoroughly by gentle inversion.


Special Processing:

Lab Staff: Do Not centrifuge. Send in original collection tube.

Prothrombin fragment 1.2 is unstable and must be processed and frozen within three hours of specimen collection. Ship the unprocessed whole blood specimen at room temperature. Must arrive at Fairview within 3 hrs of collection.

If specimen is >3 hours old prior to shipment, process specimen as follows:
Spin sample collected in blue top tube(s) for 5 minutes on the Stat Spin centrifuge, remove plasma and transfer to a 4 mL BCS sample cup(s), spin remaining plasma again for 5 minutes in the Stat Spin Centrifuge. Transfer plasma into two labeled 10x75 mL plastic tubes with a minimum of 0.5 mL in each. Freeze at -70 and send specimens on dry ice to Fairview University.

Patient Preparation:

After Care: If the patient has a coagulation abnormality, apply direct pressure to the puncture site for 10 minutes; apply a pressure dressing. Instruct the patient to leave the bandage on for 12 hours.

Sample Rejection:

Clotted sample; overfilled tube; underfilled tube; specimen greater than 3 hrs from time of collection and not centrifuged; frozen and shipped on dry ice; mislabeled or unlabeled specimens


Reference Range:


Range (nmol/L)

All ages:

0.00 - 0.35 nmol/L

Critical Values:





Enzyme-linked immmunosorbent assay


Fairview University Medical Center Web Page February 2014

Harmening DH (1997) Clinical Hematology and Fundamentals of Hemostasis


6/3/2004: Draw volume changed from 4.5 mL to 2.7 mL blood.
8/7/2005: Reference range previously listed as: ≥1 year: 0.36 – 1.37 nM/L (2SD) for both males and females.
8/4/2006: Reference range update from Fairview, previously listed as Males, all ages: 0.17-0.68 nM/L, Females, all ages: 0.12-1.04 nM/L.
5/24/2010: Tubing patient specimens is no longer prohibited.
9/30/2013: CPT previously listed as 83520.
2/24/2014: Fairview specimen processing update.
1/6/15: Ref range chg, previously listed as 0 – 0.22 nmol/L