Thrombin time (TT) and prothrombin time (PT) are commonly used coagulation function detection indicators, the difference between the two lies in the detection of different coagulation factors.

Thrombin time (TT) is an indicator of the time required to detect the conversion of plasma prothrombin into thrombin. It is mainly used to assess the activity status of fibrinogen and coagulation factors I, II, V, VIII, X and XIII in plasma. During the detection process, a certain amount of tissue prothrombin and calcium ions are added to convert the prothrombin in the plasma into thrombin, and the conversion time is measured, which is the TT value.

Prothrombin time (PT) is an index to detect the activity of blood coagulation factors outside the blood coagulation system. During the detection process, a certain amount of coagulation factor composition (such as coagulation factors II, V, VII, X and fibrinogen) is added to activate the coagulation system, and the time for clot formation is measured, which is the PT value. The PT value reflects the status of coagulation factor activity outside the coagulation system.

It should be noted that both TT and PT values are commonly used indicators to measure coagulation function, but the two cannot replace each other, and appropriate detection indicators should be selected according to the specific condition. At the same time, it should be noted that differences in detection methods and reagents may affect the accuracy of results, and attention should be paid to standardized operations in clinical practice.