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Test Code TT THROMBIN TIME

Important Note

Citrate Tube Guide

Methodology

Fibrin Formation Using Mechanical Clot Detection

 

Useful to detect or exclude the presence of heparin or heparin-like anticoagulants when evaluating unexplained prolonged PT or PTT clotting times. In addition to the presence of heparin or heparin-like anticoagulants, the thrombin time may also be prolonged due to hypofibrinoginemia, dysfibrinogenemia, fibrin degradation products and antibody inhibitors of thrombin.

Specimen Requirements

Specimen must be centrifuged within 1 hour of collection -specific instructions below:

 

Citrate Tube Guide

 

Specimen Type: Plasma

Container/Tube: Light-blue top - 2.7 mL (3.2% buffered sodium citrate)

Specimen Volume: Full tube

Collection Instructions:

  1. Tube must be filled to capacity.
  2. Ratio of blood to anticoagulant is critical for valid coagulation results (9:1).
  3. Centrifuge specimens within 1 hour of collection for 10 minutes at 3500 rpm or 3 minutes at 5100 rpm.
  4. Store specimen in original collection container at room temperature or refrigerated for up to 2 hours.
  5. If testing will be delayed longer than 2 hours, separate and freeze; two 1-mL aliquots of double-centrifuged plasma.

Additional Information:

  1. Hemolyzed specimen is not acceptable.
  2. Tubes less than 90% full will be rejected.

Day(s) Test Set Up

Monday through Sunday

Reference Values

14.5 - 18.9 seconds

Performing Laboratory

Logan Health Medical Center Laboratory

Test Classification and CPT Coding

85670

Specimen Transport Temperature

Ambient        STAT < 1 hours

Refrigerate       < 2 hours (already spun)