Evaluation of the effect of storage at-70 degrees C for six months on hemostatic function testing in dogs

Freezing is a routine method of storage for plasma that is to be used in ev aluating certain aspects of hemostatic function in many species. The purpos e of this study was to evaluate the effect of storage at -70 degrees C for 6 mo on canine plasma samples. On fresh and frozen plasma from 12 clinicall y healthy dogs, prothrombin time, activated partial thromboplastin time, th rombin clotting time, fibrinogen determination, antithrombin III activity, fragment D and E assay, and protamine sulfate test were performed. Clinical agreement analysis was utilized to determine the effect of such storage on all assays. Individual differences detected between fresh and frozen sampl es were all within 2 standard deviations of the mean difference. With the e xception of the activated partial thromboplastin time, storing canine plasm a at -70 degrees C for 6 mo has no significant effect on hemostatic functio n, as assessed by these tests.