Chapter 12 - Separation and Subfractionation of Blood Cell Populations Based on Their Surface Properties by Partitioning in Two-Polymer Aqueous Phase Systems

Abstract

This chapter discusses a versatile and sensitive method that can be used not only to separate and subfractionate cell populations based on subtle differences in their surface properties but also yields information on changes in surface properties as a function of normal and abnormal in vivo processes or in vitro treatments. The partitioning of cells in dextran-poly(ethylene glycol) (D-PEG) aqueous phases is a tool without current equal for the resolution of cells for a number of reasons. (1) aqueous–aqueous phase systems are very versatile. Their polymer concentration and ionic composition and concentration can be manipulated in a manner such that the partitioning of cells will reflect different membrane surface properties. (2) The surface characteristics measured by partitioning are determined with great sensitivity. (3) Countercurrent distribution of cells permits study not only of differences among but also changes in surface properties. (4) Finally, it must be emphasized that the D-PEG aqueous two-phase system is extremely mild and protective of cells.