Over the last 15 years, a technique has been developed at the University of Maastricht check details by Hemker et al.[10] in which a specific slow reacting fluorescent substrate of thrombin is added to either platelet-poor and platelet-rich plasma samples without defibrination, and the course of thrombin formation is monitored in real time. These technical developments of the

TGT make it potentially applicable to clinical laboratories. Correlations between the TGT parameters and clinically observed bleeding in patients with haemophilia and other inherited bleeding disorders have been published[5,11]. This correlation between clinical bleeding risk and thrombin generating capacity led to the evaluation of this technology as a surrogate marker for by-passing therapy in haemophilia patients with anti-FVIII/FIX alloantibodies[12]. It has also been shown that TGT is sensitive to hypercoagulability IWR-1 molecular weight [13]. Endogenous

thrombin potential (ETP) representing the enzymatic activity of the generated thrombin during its life-time is the parameter that correlates with clinical bleeding or thrombosis [5,11–13]. Moreover, there are several studies on the standardization of the TGT making its use suitable in clinical trials, in comparison with other global haemostasis assays, e.g. thromboelastography that are not yet as well standardized[14,15]. However, wide acceptance of TGT as a clinical tool to evaluate individual clinical phenotype of patients with coagulation disorders

also depends on the accuracy and precision of the test. The ability to reproduce reliable thrombin generation measurements should be facilitated by the use of standardized preanalytical and analytical procedures. It has been shown that inappropriate phlebotomy and sampling materials may produce significant activation of coagulation and may be responsible for erroneous results[16]. Thrombin generation measured in platelet-rich plasma (PRP) samples obtained from Vacutainer tubes® (Becton Dickinson, Meylan, France) with a negative air pressure inside overestimates the coagulation capacity in comparison with that see more obtained from Monovette S® tubes (Sarstedt, Orsay, France) that have a piston allowing a slow aspiration of blood and therefore limiting platelet damage[17]. The addition of a contact factor inhibitor into the collection tubes, i.e. corn trypsin inhibitor (CTI) may significantly reduce imprecision of TGT results obtained in the presence of low tissue factor concentrations ≤1 pM [14]. It has been recently suggested that contact activation was particularly high with ‘butterfly’ needles equipped with tubing, which are widely used in hospitals [18]. One of the most critical steps among the preanalytical variables is the preparation of plasma samples.