- Thrombin clotting time
The Thrombin Clotting Time (TCT), also known as the Thrombin Time (TT), is a coagulation assay which is usually performed in order to detect for the therapeutic level of the
anticoagulant Heparin . It is also sensitive in detecting the presence of afibrinogen abnormality.Procedure
Within the realm of
coagulation assays, the Thrombin Clotting Time is one of the most procedurally simple. After liberating the plasma from the whole blood bycentrifugation , bovineThrombin is added to the sample of plasma. The clot is formed and is detected optically or mechanically by a coagulation instrument. The time between the addition of the thrombin and the clot formation is recorded as the thrombin clotting timepecimen Requirements
Whole blood is taken with either
citrate oroxalate additive (if using thevacutainer system, this is a light blue top tube). As with other coagulation assays, the tube must not be over- or under-filled in order to ensure the correct anticoagulant-to-blood ratio: 1 part anticoagulant per 9 parts blood.Reference Interval
The
reference interval of the Thrombin Clotting time is generally <21 seconds, depending on the method and the endemic patient population. Results outside of reference interval indicate heparin therapy,Hypofibrinogenemia ,hyperfibrinogenemia fibrinogen abnormality, orLupus anticoagulant .Causes for specimen rejection
Causes for Rejection of the specimen include
QNS , severehemolysis , improper storage or delay in processing, error in labeling.ources
http://peir.path.uab.edu/coag/article_136.shtml
http://medinfo.ufl.edu/year2/coag/tt.html
http://www.rnceus.com/coag/coagtt.html
http://www.utmb.edu/lsg/labsurvivalguide/hem/thrombin_time.htm
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