Factors in the partition of red blood cells in aqueous dextran-polyethylene glycol two-phase systems

Abstract

Abstract The usefulness of countercurrent distribution of cells in aqueous, buffered two-polymer phase systems is illustrated by the segregation of erythrocytes of different ages, the resolution of two populations of reticulocytes, the separability of red blood cells from white blood cells, a study of membrane characteristics of red cells from different species 1,2 . We now report the effects on erythrocyte partition of a number of factors ( e.g. I , pH, temperature, hypertonicity or hypotonicity, ABO blood group, washing of cells and anticoagulant). It is also shown how some of these parameters can be used to obtain desired partitions for (red) cells in a given investigation. In the dextran-polyethylene glycol phase systems that we have investigated, an increase in I (with constant isotonicity) appears not to alter the partition of red cells except with phosphate in which a decrease in the partition coefficient is observed. Increase in pH or temperature causes an increased partition. Different degrees of hypotonicity give similar partitions which are somewhat greater than those found in isotonic phase. Increasing hypertonicity leads to a rapid decrease in the partition coefficients. Human red cells are found to have the same partition independent of the ABO blood group to which they belong. Washing of cells or anticoagulant used (acid-citrate-dextrose, heparin, EDTA) has no effect on their partition. In view of the previously established correlation between electrophoretic mobility of red cells and their partition coefficients 3 we point out, in the course of the discussion, those instances in which the electrophoretic mobility and partition of cells are similarly affected by changing a given parameter, and those instances in which the effects are markedly different. In the latter instances partition of cells in aqueous two-polymer phase systems and electrophoretic mobility appear to measure different membrane characteristics.