Abstruct. Using the filtration method described earlier, leukocytes were removed from units of fresh whole blood and erythrocyte suspensions (hematocrit 50%). After filtration, the units were stored for one or two weeks.Units of whole blood and erythrocyte concentrates were stored for periods up to three weeks, the leukocytes were then removed by filtration, and the units were stored for another week.During the storage period, the following parameters were measured: pH and concentrations of ATP + ADP, 2,3-diphosphoglycerate, hemoglobin and potassium (Hb and K+ in the cell-free supernatant). The parameters used in the present study indicate that removal of leukocytes by filtration did not cause significant alteration to stored whole blood and erythrocyte concentrates, compared to unfiltered blood stored for the same time. D~PENHOR~//SPROKHOLT/PRINS(DPG), free hemoglobin, and potassium (Hb and K + in the cell-free supernatant). We measured ATP + ADP because of the close correlation between ATP level and erythrocyte viability [l, 51. DPG was measured as low levels are known to cause decreased oxygen release to the tissues [9]. Materials and MethodsCollection of blood andpreparation of red cell concentrates. Blood was collected in the evening prior to the experiments, as described earlier [2], and either cooled in the usual way or immediately after collection. Cooling in the usual way was effected as follows: bottles were put in a cold room (2°C) approximately 4 h after collection, PVC bags were put in a metal box containing ice cubes approximately 1 h after collection.Rapid cooling was obtained by putting bottles and PVC bags in melting ice immediately after collection, followed by storage in a cold room (2°C).When needed, erythrocyte concentrates were prepared by centrifugation (30 min at 1,350 g ) and aspiration of the plasma.In one experiment, a pool was made of several units of ACD erythrocyte concentrate with the same ABO blood group and Rh factor. Filtration.Filtration was performed using the filter system described earlier [2]. Part of each unit was not filtered but kept to serve as a noniiltered control sample.Storage. In one experiment, units of whole blood and erythrocyte concentrates were stored in the bottle in which they were taken for periods up to three weeks at 2°C prior to filtration.In two other experiments, the storage period was limited to one night. After filtration, the suspensions were put in screwcapped, sterile plastic tubes, one for each day of storage, and stored at 2°C; so were the nonfiltered control samples. Determination of p H , ATP + ADP, DPG, free hemoglobin and potassium.Each day during the experiment, a tube of each series was opened after thorough mixing.The pH was determined on the day of opening and samples for the other determinations were stored at -20°C. After approximately one week, the other parameters were measured simultaneously.The glycolytic intermediates: ATP + ADP, DPG, were determined in 900 and 27,000fold dilutions of blood samples by mechanized enzymatic methods [...

Abstract. It was observed that during the preparation of normal anti‐D immunoglobulin concentrates by a modified Cohn VI method a considerable loss of anti‐D activity occurred in fraction III. A method was developed to prepare anti‐D immunoglobulin concentrates from fraction III by ethanol fractionation. Three batches were treated on a production scale. An average of 18% of the amount of anti‐D activity present in the original plasma, was recovered, which increased the total yield of anti‐D activity from 44 to 62%. The specific activity of anti‐D in the concentrate thus prepared was 2–3 times higher than that in the normal anti‐D immunoglobulin concentrate. The anti‐D immunoglobulin concentrate prepared from fraction III was diluted with normal immunoglobulin concentrate to reach an anti‐D concentration of 110–120 μg/ml. Using several analytical procedures no essential differences could be demonstrated between this final product and the normal immunoglobulin concentrate. After 8 months of storage at 4°C no significant decrease in anti‐D activity could be demonstrated.