Animal-free Recombinant Human Thrombin is expressed in human 293 cells as a monomeric glycoprotein with an apparent molecular mass of 36 kDa. Production in human 293 cells ensures authentic glycosylation. Thrombin is a coagulation protein and a serine protease that catalyzes numerous coagulation correlated reactions. Thrombin also regulates the behavior of additional cells through protease activated receptors and endorses platelet activation. This recombinant protein is produced in a human cell expression system with serum-free, chemically defined media.