Method
Blood samples are collected in tubes with oxalate or citrate to arrest coagulation by binding calcium. The specimen is then delivered to the laboratory. In order to activate the intrinsic pathway, phospholipid, an activator (such as silica, celite, kaolin, ellagic acid), and calcium (to reverse the anticoagulant effect of the oxalate) are mixed into the plasma sample. The time is measured until a thrombus (clot) forms. This testing is performed by a medical technologist.
The test is termed "partial" due to the absence of tissue factor from the reaction mixture.
Read more about this topic: Partial Thromboplastin Time
Famous quotes containing the word method:
“in the absence of feet, “a method of conclusions”;
“a knowledge of principles,”
in the curious phenomenon of your occipital horn.”
—Marianne Moore (1887–1972)
“I know no method to secure the repeal of bad or obnoxious laws so effective as their stringent execution.”
—Ulysses S. Grant (1822–1885)
“Argument is conclusive ... but ... it does not remove doubt, so that the mind may rest in the sure knowledge of the truth, unless it finds it by the method of experiment.... For if any man who never saw fire proved by satisfactory arguments that fire burns ... his hearer’s mind would never be satisfied, nor would he avoid the fire until he put his hand in it ... that he might learn by experiment what argument taught.”
—Roger Bacon (c. 1214–1294)