[Preparation of leukocyte-free blood by a method of sedimentation-filtration].

After centrifugation of 450 ml-CPD-whole blood, 125 ml of packed red cells are diluted to 50 percent with saline (pH 7, 2). To remove leukocytes the diluted blood is filtered at room temperature through a newly devised column packed with cotton wool disks. 200 ml of red blood cells suspension are recovered and contain less than 5.10(6) leukocytes. Appropriate controls show that: 1. The filtered blood contains no pyrogen; 2. The red blood cells have a normal osmotic resistance; 3. The suspension can be maintained at 4 degrees C up to 5 days before transfusion without cellular damage.