**8.2. Activated prothrombin time assay (aPTT assay)**

aPTT assay is used to measure the integrity of intrinsic pathway. In this method the clotting is initiated by supplementing Kontact reagent and calcium chloride to the platelet poor plasma. Similar to PT assay, prolongation of aPTT indicates the risk of bleeding disorders and shortening of the aPTT indicates risk of thrombosis [136].
