Observations on the Conversion of Prothrombin to Thrombin

Abstract

Fresh plasma, serum and platelet extracts contain a material which potentiates the action of tissue thromboplastin on stored plasma. Platelet extract apparently contains a greater degree of this activity than plasma or serum and potentiates the action of tissue thromboplastin on fresh plasma. This factor favoring pro-thrombin conversion apparently is present in the circulating blood.