Preparation of Quality Control Specimens for Coagulation

Abstract
A method for the preparation of lyophilized plasma specimens for use as quality controls in coagulation testing is described. This method, utilizing a recently developed hydrogen ion buffer, N-2-hydroxyethylpiperazine-N’-2-ethanesulfonic acid, has provided excellent pH and enzyme stability for prothrombin time testing. Reconstituted plasma specimens were stable for 8 hr. Coagulation factors were well preserved. The utilization of these lyophilized plasma specinens in a quality control system is discussed.