Sample integrity analysis for prothrombin time and inr at different storage conditions

According to the acceptable temperatures and storage time available in the literature for prothrombintime, samples need to be processed within four hours at laboratory temperature. But samples need to be stored if there is a need to retest on request and also for research purposes. With advancement in development of new reagents and equipment, whether the storage condition and time can be extended need to be evaluated. It is aimed to study the integrity of plasma samples for prothrombin time and INR at different storage conditions. A laboratory based comparative study was conducted to analyse the sample integrity of platelet poor plasma for prothrombin time and INR. The samples were processed by fully automated coagulation analyser at different storage conditions with regard to temperature and duration. There was no significant prolongation or shortening in the prothrombin time or INR with storage at room temperature upto 24 hours, refrigerated temperature upto 72 hours and freezing upto 3 months. Samples for prothrombin can be freezed for research purposes and refrigerated for repeat test.