Normal plasma Prothrombin time (PT).. 11 - 16 Sec NIL NAM July 02, 2017 Normal plasma Prothrombin time (PT): a. 36 - 50 Sec. b. 11 - 16 Sec.*** c. 12 - 15 Sec. d. 1 - 4 min. Share This: Facebook Twitter Google+ Stumble Digg