[Determination of prothrombin (factory II) in one step using Taipan venom].

A new one-stage prothrombin assay using Taipan venom is presented here. Taipan venom converts prothrombin to thrombin in the absence of all coagulation factors known up to the date. The prothrombin concentration in normal adults varied from 64.0% to 159.0% with a mean of 100.64% plus or minus 24.83%.