Comparisons were made of the apheresis instruments Haemonetics Blood Processor 30, IBM Blood Processor 2997 and Fenwal CS-3000, for collection of platelets from normal donors. With each instrument the mean recovery was at least 4x10^11 platelets per procedure, and each instrument afforded a safe and reliable collection. The Haemonetics Blood Processor gave the lowest recovery of platelets per minute per procedure. The IBM Blood Processor 2997 required the longest time for set-up and priming and processed 1.5 liters more donor blood per collection than the other instruments. The Fenwal CS-3000, which is a computer-controlled instrument, was the least time consuming. The donor suffered a significantly greater drop in platelet count after collection with the IBM Blood Processor 2997 (31%) than after collection with the other instruments (19%), and we were unable to account for this observation.

We report here on a new approach to washing red blood cells frozen with a high concentration of glycerol in a special freezing container. The wash solution consists of a 150-ml volume of 12% sodium chloride and 2 liters of 0.9% sodium chloride-0.2% glucose- 25 mEq/1 disodium phosphate. Both the Haemonetics Blood Processor 115 and the IBM Blood Processor 2991 have been used with this protocol, with similar results. The in vitro recovery of red blood cells frozen with 8.6M glycerol was 89%, and that of red blood cells frozen with 6.2M glycerol was 93%. The 24-hour posttransfusion survival values averaged 88% for eight units of outdated-rejuvenated previously frozen red blood cells washed by this protocol and stored at 4°C for 3 days before autotransfusion.