The storage of washed human erythrocytes in a protein-free medium.

Protein-free red blood cells were prepared by washing fresh citrate-phosphate-dextrose anticoagulated whole blood and resuspending the cells in a medium containing saline, adenine, phosphate, and glucose (APG). The protein concentration in the APG medium was reduced to 0.0024 percent of the original plasma protein. The 24-hour red blood cell posttransfusion survival after 21 days of storage was 80 percent. Extracellular potassium concentrations were less than the CPD-plasma control after 21 days of storage. Adenosine triphosphate (ATP) concentrations were lower after storage in APG, but intracellular ATP was not closely associated with posttransfusion survival. Hemolysis was slightly increased in the APG group. There appear to be no insurmountable barriers to the use of protein-free media for the storage of washed red blood cells.