Sign in →

Test ID: F_10 Coagulation Factor X Activity Assay, Plasma

Ordering Guidance

Coagulation testing is highly complex, often requiring the performance of multiple assays and correlation with clinical information. For that reason we suggest ordering Coagulation Consultations.

Necessary Information

If priority specimen, mark request form, give reason, and request a call-back.

Specimen Required

See Coagulation Guidelines for Specimen Handling and Processing in Special Instructions.


Specimen Type: Platelet-poor plasma

Collection Container/Tube: Light-blue top (citrate)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Within 4 hours of collection, centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again. Aliquot plasma into separate plastic vial leaving 0.25 mL in the bottom of centrifuged vial.

2. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C, or, ideally at ≤-40° C.

Additional Information:

1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

2. Each coagulation assay requested should have its own vial.

Useful For

Diagnosing deficiency of coagulation factor X, congenital or acquired


Evaluating hemostatic function in liver disease


Investigation of prolonged prothrombin time or activated partial thromboplastin time

Method Name

Optical Clot-Based

Reporting Name

Coag Factor X Assay, P

Specimen Type

Plasma Na Cit

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Na Cit Frozen 14 days

Clinical Information

Factor X is a vitamin K-dependent serine protease that is synthesized in the liver. Its biological half-life is 24 to 48 hours. Factor X participates in both intrinsic and extrinsic pathways of coagulation (final common pathway) by serving as the enzyme (factor Xa) in the prothrombinase complex.


Congenital factor X deficiency is rare. Acquired deficiency associated with liver disease, warfarin therapy, vitamin K deficiency, systemic amyloidosis and inhibitors (rare). Deficiency may cause prolonged prothrombin time and activated partial thromboplastin time.

Reference Values

Adults: 70-150%

Normal, full-term newborn infants or healthy premature infants may have decreased levels (≥15-20%) which may not reach adult levels for ≥180 days postnatal.*

*See Pediatric Hemostasis References section in Coagulation Guidelines for Specimen Handling and Processing in Special Instructions.


Acquired deficiency is more common than congenital deficiency.


Homozygotes: <25%


Heterozygotes: 25% to 50%

Clinical Reference

1. Girolami A, Scandellari R, Scapin M, Vettore S: Congenital bleeding disorders of the vitamin K-dependent clotting factors. Vitam Horm 2008;78:281-374

2. Brenner B, Kuperman AA, Watzka M, Oldenburg J: Vitamin K-dependent coagulation factors deficiency. Semin Thromb Hemost 2009 Jun;35(4):439-446

3. Menegatti M, Peyvandi F: Factor X deficiency. Semin Thromb Hemost 2009 Jun;35(4):407-415

4. Girolami A, Ruzzon E, Tezza F, et al: Congenital FX deficiency combined with other clotting defects or with other abnormalities: a critical evaluation of the literature. Haemophilia 2008;14(2):323-328

5. Girolami A, Scarparo P, Scandellari R, Allemand E: Congenital factor X deficiencies with a defect only or predominantly in the extrinsic or in the intrinsic system: a critical evaluation. Am J Hematol 2008;83(8):668-671

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
F_10 Coag Factor X Assay, P 3218-5


Result ID Test Result Name Result LOINC Value
F_10 Coag Factor X Assay, P 3218-5
Mayo Clinic Laboratories | Hematology Catalog Additional Information: