<qa>  What is the maximum thrombin concentration?Calibrated automated thrombin generation measurements will be performed using the Hemker methodology. 29 Platelet rich plasma PRP will be prepared as described above. Fluorogenic substrate and chromogenic thrombin will be purchased through Thermolabsystems, and recombinant relipidated tissue factorTF through Dade Behring. alpha 2 macroglobulin-thrombin complex used as a calibrator will be purchased through Thrombolabsystems. The thrombograms will be measured in a 96-well plate fluorometer Ascent reader, Thrombolabsystems and analyzed with software purchased through Thrombinoscope. Experiments will be carried out in quadruplicate and compared to a calibrator. To each well 80 mcl of plasma will be added, followed by the calibrator or buffer, then the trigger: 20 mcl of 3 mM of TF. The plate will be placed in the fluorometer and allowed to warm to 37 C. The instrument dispenses 20 mcl of Fluorogenic substrate 2.5 mM and CaCl2 100 mM FluCa to all the wells to be measured, registers this as zero time, shakes them for 10 s and starts reading. During the measurement, the program compares the readings from the TG and the CL, calculates thrombin concentration and displays the thrombin concentration in time. The peak thrombin is the highest thrombin concentration reached during the time course of thrombin formation and inhibition. The thrombin potential is the amount of thrombin that is formed within 60 minutes Area under the curve. The lag phase and the peak time refer to the start and velocity of thrombin formation, respectively. 