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Thrombin Time


Thrombin Time
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Reference Range:

0.9 – 1.15 ratio 14.5 - 20.5 seconds

Turnaround Time:

Urgent 1hr: Non urgent 2hrs


The TCT is a rapid screening test for the conversion of fibrinogen to fibrin. Used for the evolution of disseminated intravascular coagulation (DIC), Heparin therapy, qualitative and quantitative fibrinogen abnormalities and increased fibrinolysis


Citrated whole blood is centrifuged at 2500g for 10 minutes to yield platelet poor Plasma (PPP). Only samples that are correctly filled and free from haemolysis should be used.

Vessels and Containers:

1x 4.5 Citrated blood (Blue top)

Sample Requirements:

Samples should be obtained by clean venepuncture and be free of haemolysis and lipaemia. Samples should be received in the laboratory within 2hrs of sampling


The presence of inhibitory substances such as heparin and FDPs will prolong the thrombin time. The presence of heparin may be by-passed using a Reptilase time. A prolonged TCT and normal Reptilase time is diagnostic of the presence of heparin in the plasma. The Reptilase time is less sensitive than the TCT to the presence of FDPs but is more sensitive in patients with dysfibrinogenaemia.

How result is reported:

The TCT is prolonged by:- Fibrinogen deficiency (afibrinogenaemia) Dysfibrinogenaemia Heparin Abnormal plasma proteins FDPs