- Better known today as prothrombin, a coagulation (clotting) factor needed for the normal clotting of blood. There is a cascade of biochemical events that leads to the formation of the final clot. In this cascade, prothrombin is a precursor to thrombin. Because prothrombin comes before thrombin, it is called prothrombin. The prothrombin time is a clotting test. a test done to test the integrity of part of the clotting scheme. Familiarly called the "pro time," the test is the time needed for clot formation after a substance called thromboplastin (+ calcium) has been added to plasma.
* * *SYN: prothrombin.
* * *throm·bin·o·gen (throm-binґo-jən) factor II; see under coagulation factors, at factor.
Medical dictionary. 2011.