The prothrombin time (PT) assay according to Quick is a global coagulation screening test for evaluation of both the extrinsic and common coagulation pathways (consisting of coagulation factors VII, X, V, II and fibrinogen). The PT assay is used for monitoring of patients receiving oral anticoagulant therapy, to screen for coagulopathies prior to surgical interventions or for the detection of inherited or acquired factor deficiencies. It is also a diagnostic tool for disseminated intravascular coagulation (DIC), for liver function testing, or for vitamin K deficiency, either due to severe malnutrition or disorders in metabolism of vitamin K as factors II, VII and X are vitamin K dependent.