Clinics and Departments

Laboratory Services

Lab Dept:


Test Name:


General Information

Lab Order Codes:



Factor 13 Immunologic Assay; Factor 13A; Factor 13 Antigen

CPT Codes:

85290 – Factor 13 (fibrin stabilizing)

Test Includes:

Antigen level for subunit A reported as a %.


Test Indications:

Factor XIII is essential for maintaining hemostasis due to its role in fibrin stabilization and in the protection of fibrin from proteolytic degradation by the fibrinolytic system addition. Factor XIII is also involved in maintaining pregnancy and wound healing.

Lab Testing Section:

Coagulation - Sendouts

Referred to:

Fairview University Medical Center (Fairview/Atlas Test: F13A)

Phone Numbers:

MIN Lab: 612-813-6280

STP Lab: 651-220-6550

Test Availability:

Daily, 24 hours

Turnaround Time:

3 – 12 days; performed Wednesdays

Special Instructions:

Patient should not be receiving heparin. If so, this should be noted on the request form. Heparin can affect certain coagulation factors or assay, preclude their performance, or cause spurious results.

Indicate when the specimen is drawn from a line or a heparin lock. Deliver immediately to the laboratory.


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)
Please respect fill line on tube.

Processed Volume:

2 mL (minimum 1 mL) plasma frozen at -70. Follow directions below under Special Processing.


Routine venipuncture. Do Not use the first 2 mL’s 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: Centrifuge 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 one labeled 10x75 mL plastic tubes with 2 mL (minimum 1 mL) plasma. Freeze at -70 and send specimens on dry ice to Fairview University.

Patient Preparation:

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

Sample Rejection:

Improper tube; clotted samples; underfilled tubes; overfilled tubes; mislabeled or unlabeled specimens; gross hemolysis; grossly icteric or lipemic; incorrect anticoagulant


Reference Range:


Reference range (%):

1 – 4 d

53 – 105%

5 – 29 d

69 – 119%

30 – 89 d

66 – 120%

90 – 179 d

70 – 138%

180 – 364 d

75 – 133%

1 y and older

75 – 155%


Age specific reference ranges have not been established for newborns less than 1 day old.

Critical Values:

Less than 10%




Chromogenic Assay


Fairview University Diagnostic Laboratories January 2016


5/19/2004: As of February 2004, Fairview no longer performs Subunit S as part of this test. References to Subunit S have been removed. Draw volume changed from 4.5 mL to 2.7 mL blood.
7/15/2004: Reference range changed from 66-150% to 60-130% for patients 1 year and older.
5/25/2010: Tubing patient specimens is no longer prohibited.
3/31/2011: CPT update and reference range update.
2/27/2014: Fairview now refers this test to ARUP. Updated to ARUP specification.
5/1/2014: Specimen must be processed and frozen at Children’s before sending to Fairview.
1/13/2016: Fairview now performing test inhouse.

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