Manipulating red cell intra- and extracellular pH by washing

Washing red cells with solutions containing no anions capable of entering the cells is known to result in the loss of intracellular chloride and a counterflow of OH- which raises intracellular and lowers extracellular pH. Elevating the intracellular pH improves the quality of the cells during 4 degrees C storage. The extent to which intracellular pH can be raised and extracellular pH reduced depends not only on the inability of extracellular anions to enter the cells but also on the buffering capacity of the wash solution. Both intra- and extracellular pH can be manipulated by the judicious selection of anions or combinations of anions used in the wash solution.