Prekallikrein assay

Alphabetical Test listing

Prekallikrein assay-994

Prekallikrein assay
Fletcher factor assay

Measurement of prekallikrein factor concentration

Sodium citrate (Na cit) plasma
2 mL
1 mL

Do not draw from an arm with a heparin lock or heparinized catheter.

  1. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.
  2. Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio. Coag - Tube fill guidelines
  3. The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anti- coagulant with the blood.

Spin, separate, and freeze


Frozen (preferred)

Ambient - 4 hours

LabCorp Burlington (500194): R-NX
4 - 8 days

Factor prekallikrein activity is determined utilizing an aPTT-based one-stage clotting time assay. Factor prekallikrein-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.


Normal: ≥ 50 %

Result 28659-1