The use of lyophilized plasma as a reference sample for determining factor VIII]

The activity of lyophilized Soviet reference plasma Factor VIII was measured by a single-stage Papayan and Khrolova's method. This factor is referent in respect of the prothrombin complex factors, stored for 18-43.5 months. Factor VIII activity was found to be within 55-135 percent. Differences in the values of antihemophilic globulin activities obtained in parallel studies in different days may be explained by the fact that the native control was not standard. The results are promising as regards the possibility of using lyophilized donor reference plasma as a reference reagent for estimation of Factor VIII activity.