Factor 12 activity

Alphabetical Test listing

Factor 12 activity-994

Test name:

Factor 12 activity

Test number:

994

Excellian order number:

LAB994

Abbreviation:

MSO

Alternate names:

Factor XII activity
Hageman factor
Surface factor

Useful for:

Evaluate a prolonged aPTT and detect specific coagulation factor XII activity

Specimen type:

Sodium citrate (Na cit) plasma

Collection container:

Lt blue Sodium citrate (NaCit) - 2.7mL

Volume:

1.0 mL

Minimum volume:

1.0 mL

Collection instructions:

Collection tubes must be filled to completion to ensure a proper blood-to- anticoagulant ratio.
If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted.
The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood.

Processing instructions:

Spin
Transfer plasma to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as Na cit plasma
Freeze

Transport container:

Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp)

Transport and stability:

Frozen - 28 days

Freeze/thaw cycles - stable x3

Reason for rejection:

Severe hemolysis
Improper labeling
Clotted specimen
Specimen diluted with I.V. fluids
Samples thawed in transit
Improper sample type
Sample out of stability

Performing lab:

LabCorp Burlington (086322): R-NX

Days set up:

Tu - Fr

TAT:

2 - 3 days

Method:

aPTT-based one-stage clotting time assay. Factor XII-depleted plasma is used as the substrate and the clotting time with the patient plasma is compared to the clotting time of normal pooled plasma.

Reference ranges:

50 - 150%

CPT codes:

85280

LOINC code:

Result 3232-6

Date created:

05/29/2019

Revised date:

03/04/2025

Review date:

03/04/2025