Time-evolution of erythrocyte physico-chemical properties in blood stored at different temperatures.

Several interrelated biophysical and biochemical properties of erythrocytes and plasma from whole blood stored at 4 degrees C, and 37 degrees C with CPD preservative were determined over a 21-day period. Changes in red cell volume, deformability and osmotic fragility (all measured by resistive pulse spectroscopy) showed some surprising fine structure that correlated well with dynamic variations in extracellular species, especially sodium, potassium and lactate dehydrogenase. Several features of these data suggest the existence of three distinct stages of cell condition, apparently not recognized previously. Changes are interpreted primarily in terms of membrane behavior, and implications for storage monitoring are discussed.