Test Code: TCT Preferred Name Thrombin time

As required
2 hrs
Medicare Item

Test Tubes

ImageSpecimen TypeSpecimen VolumeTube Type
Blood (Adult)2.7mLSodium Citrate 2.7 mL (Solid Pale Blue Top)
Blood (paediatric)1.8 mlSodium Citrate 1.8 mL Paed (Clear/Pale Blue Inner)
Blood (Neonatal)1.0 mlSodium Citrate 1.0 mL Neonate (Pale Blue Top)


Accurate filling of specimen tube is essential.
All collections that include Coagulation testing must be sent to the laboratory in a BLUE specimen bag.
Please ask the patient what anticoagulants they are on and the dose, record on request form.


Heparin interferes with the thrombin-fibrinogen reaction and nearly always causes extreme prolongation of the TT. Dabigatran etexilate therapy will also markedly prolong the Thrombin time. Other causes of a prolonged TT are: hypofibrinogenaemia, DIC, liver disease, dysfibrinogenaemia (physiologically present in neonates), and hypoalbuminaemia. A gross elevation of plasma fibrinogen concentration may also prolong the TT!

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