Positioning and levitation media for the separation of biological cells

In response to the requirement for highly polarizable liquid media for electric-field mediated manipulation of microparticles, solutions of highly polar substances are characterised in terms of their permittivity and other characteristics. Requirements for dielectrophoretic levitation and the generalised electromanipulation of biological cells and other microparticles are considered. Examples of the positioning and separation of biological cells are given. Cell separations at the micro and macro scales, the latter using the recently-developed technique of lev-vection, are presented. Finally, growth and division of yeast cells during long-term exposure to the electric fields necessary for this type of separation is reported.