The present invention is directed to methods for the production of thrombin from a source of prothrombin using a given BaSO4 reagent as an adsorbent of prothrombin as well as methods for evaluating the suitability of a given BaSO4 reagent for use in preparation of thrombin. In at least one embodiment, the method includes contacting a sample of the given BaSO4 reagent with a source of prothrombin to obtain BaSO4-adsorbed prothrombin, and subsequently evaluating the pro-coagulant activity of the BaSO4-adsorbed prothrombin. In another embodiment, the method includes the step of evaluating relative to the pro-coagulant activity of normal mammalian plasma.