Patent ID: 7906299

Claim:
A method for preparing an air-dried prothrombin time reagent, comprising the steps of: (A) providing a recombinant animal tissue factor; (B) providing a mixture of synthetic phospholipids; (C) selecting a phosphatidylalcohol; (D) adding said selected phosphatidylalcohol to said mixture to form a lipid mixture, which composition is present in an effective amount to lipidate said recombinant animal tissue factor to form a lipidated tissue factor; (E) combining said recombinant animal tissue factor with said lipid mixture to form a lipidated tissue factor solution; (F) adding a formulation buffer solution comprising a sensitivity adjuster to said lipidated tissue factor solution to form a liquid reagent; and, (G) drying said liquid reagent in an atmosphere of about 5% to about 10% relative humidity, and at about 20° C. to about 37° C. to form an air-dried reagent.