The antihemophilic globulin in plasma; content of freshly frozen single-donor plasma units prepared by the Los Angeles Red Cross Blood Center.

A study was made of the antihemophilic globulin (AHG) content of 16 units of freshly frozen, single-donor, type specific plasma prepared by the Los Angeles Red Cross Blood Center for the treatment of patients with coagulation disorders. Three specimens were examined for each unit-(1) a control sample taken from the donor in a separate small tube, (2) a plasma unit sample before storage, and (3) a plasma unit sample after storage for periods up to one year. From a comparison of the AHG content of Samples 1 and 2, it was found that little AHG was lost in preparing the plasma units. From a comparison of Samples 2 and 3, it was found that a moderate AHG loss (averaging about 20 per cent) occurs on storage. This varied unpredictably from bottle to bottle and was unrelated to the duration of storage. Good AHG activity was found in 4 units after storage for one year. An individual unit of frozen plasma from the Los Angeles Red Cross Blood Center will contain between 50 and 115 per cent AHG activity (with a standard reference sample of plasma taken as 100 per cent).