Phospholipid is available as an independent reagent or in combination with tissue factor as thromboplastin. Prolonged prothrombin and activated partial thromboplastin times are typical. Specifically prothrombin time (PT) or activated partial thromboplastin time(aPTT) are prolonged. Typical are normal thrombin time, prolonged prothrombin time (PT) and prolonged partial thromboplastin time(PTT). Partial thromboplastin was used to measure the intrinsic pathway. When manipulated in the laboratory, a derivative could be created called partial thromboplastin. This test is called the aPTT, or activated partial thromboplastin time. These include activated partial thromboplastin time (APTT) and antifactor Xa activity. However, partial thromboplastin is just phospholipids, and not tissue factor. Plasma prekallikrein deficiency causes a prolonged activated partial thromboplastin time in patients. Fourth, Prothrombin time (PT) and activated partial thromboplastin time (aPTT) can be calculated. Thromboplastin, by itself, could activate the extrinsic coagulation pathway.