PREPARATION OF DRIED SYNTHETIC PROTHROMBIN TIME REAGENTS

A method for preparation of an air-dried prothrombin time (PT) reagent which uses a recombinant protein and synthetic phospholipids is described. The source for the recombinant protein is rabbit brain, and the phospholipids employed are palmitoyloleoylphosphatidylcholine (POPC) and palmitoyloleoylphosphatidylserine (POPS). The particular formulation buffer used to dilute the lipidated tissue factor provides a reagent that is dried without lyophilization and remains stable for at least 2 weeks at 37 C. A method for preparing the improved PT reagent and a method of using the reagent to analyze blood PT is also provided.