Thromboplastins are the screening tests which are used in the diagnosis of acquired or inherited disorders of the coagulation system but still, alterations between various thromboplastin preparations in the measurements remains a problem.Blood samples are going to drawn from patients receiving and not receiving oral anticoagulant therapy (OAT) during their routine laboratory tests. Samples are subjected to analysis by using Thromborel® S and Innovin® reagents. Mean International Normalized Ratio (INR), prothrombin time and fibrinogen values are going to compared. To further study the importance of this phenomenon the cohort will be divided into three subgroups according to the INR values as Group I: Patients not receiving OAT, Group II: Patients under OAT and INR values in good therapeutic range and Group III: Patients under OAT and INR values over the therapeutic range.