Fig. 2. Typical modified thromboelastography (mTEG®) traces. The mTEG® assay uses reptilase and factor XIIIa to form a clot without thrombin generation in heparinized whole blood. Two traces are run concurrently: One is of heparinized blood treated with 10 μl activator F (reptilase and factor XIIIa), which measures the contribution of fibrin to the maximum amplitude (inner trace ), and the second is of heparinized whole blood with 10 μl activator F and 10 μl agonist (middle trace ). These are compared with the kaolin heparinase trace (outer trace ). AA = arachidonic acid; ADP = adenosine diphosphate.