High molecular weight kininogen

Alphabetical Test listing

High molecular weight kininogen-994

High molecular weight kininogen
Fitzgerald factor
  • Evaluation of an elevated aPTT
  • Measurement of high molecular weight kininogen concentration
Sodium citrate (Na cit) plasma
2.0 mL
1.0 mL
  • Do not draw from an arm with a heparin lock or heparinized catheter.
  • Blood should be collected in a blue top tube containing 3.2% buffered sodium citrate. 
  • Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio.
  • The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood.
  • A discard tube is not required prior to collection of coagulation samples except when using a winged blood collection device (i.e. "butterfly"), in which case a discard tube should be used.
  • When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes.
  • Any tube containing an alternate anticoagulant should be collected after the blue top tube.
  • Serum gel tubes with clot initiators should also be collected after the citrate tubes.
  1. Centrifuge for 10 minutes and carefully remove two thirds of the plasma without disturbing the cells, using a plastic transfer pipette.
  2. Transfer the plasma to a plastic transfer tube, cap, and recentrifuge for 10 minutes.
  3. Use a second plastic pipette to remove the plasma, staying clear of the platelets at the bottom of the tube.
  4. Transfer the plasma into a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp).
  5. Freeze immediately and maintained frozen until tested.



Frozen (preferred)
Four freeze/thaw cycles are acceptable
Ambient - 4 hours
LabCorp Burlington (500460): R-NX
4 - 8 days



65 - 135%

Result 52754-9