Ordering Recommendation

Preferred first-line test to diagnose inherited or acquired factor XIII (FXIII) deficiency. Appropriate for evaluation of patients with a bleeding disorder who present with normal prothrombin time (PT), activated partial thromboplastin​ time (aPTT), and platelet count test results. Monitor FXIII therapy and confirm abnormalities detected on FXIII qualitative assay.

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 www.aruplab.com for hemostasis/thrombosis specimen handling guidelines.

Specimen Preparation

Transfer 2 mL platelet-poor plasma to an ARUP Standard Transport Tube. (Min: 1 mL)

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: at -20°C or below: 1 month; Frozen at -70°C or below: 3 months


Chromogenic Assay




1-8 days

Reference Interval

Factor XIII Activity 69-143%

Interpretive Data

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Compliance Category

Laboratory Developed Test (LDT)


Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
2006183 Factor XIII Activity 27815-0
* 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.


  • Factor 13
  • fibrin stabilizing factor
Factor XIII Activity