Reptilase time (RT).

The reptilase time is a functional plasma clotting assay, which is based on the enzymatic activity of batroxobin. By specifically cleaving fibrinogen A from fibrinogen, batroxobin leads to the formation of a stable fibrin clot. The time, starting from the addition of batroxobin to the plasma sample, until clot formation is the reptilase time and is given in seconds. Clot formation can be detected manually or on automated coagulation systems. Reference values for healthy adults are 18-22 s. Healthy newborns may have a slightly prolonged reptilase time of up to 24 s. In addition to other coagulation assays, the reptilase time is usually performed to confirm or to exclude the suspicion of dysfibrinogenemias. The reptilase time is independent of thrombin generation disturbances or disturbances in the action of thrombin on fibrinogen. Therefore, it can be used to confirm heparin contamination or to obtain similar information as with the thrombin clotting time in heparinized and hemophiliac patients.