Chapter 3 Partition of Cells in Two-Polymer Aqueous Phases: A Method for Separating Cells and for Obtaining Information on Their Surface Properties

Abstract

This chapter describes an extremely sensitive method for the separation and sub fractionation of cell populations based on differences in their membrane surface properties (primarily surface charge). In addition, subtle changes in membrane surface properties can be traced that occur as a function of cell differentiation, maturation, age, growth and proliferation, metabolism, in vivo and in vitro treatments. Separation of soluble materials by differential partition between two immiscible phases is one of the classical purification procedures. If one introduces a mixture of substances (for example, A and B) into such a phase system and A is more soluble in the top phase while B is more soluble in the bottom phase, a separation of A and B can be effected. If A is almost exclusively in the top and B in the bottom, the separation is virtually complete in one extraction. If the differences in the relative solubilities of A and B in the top and bottom phases are not so extreme, then separation of the two substances can be achieved only by a multiple extraction procedure (for example, countercurrent distribution).