John W. D. Eveleigh

Some Rheological Properties of Perfluorocarbon Emulsions and Their Potential use in Countercurrent Chromatography Distribution and Chromatography Separation Systems

Aqueous two phase systems utilising polymers such as dextran and poly(ethylene) glycol have offered a unique method of purifying viable biological material for more than three decades. Perhaps the most inhibiting factors limiting their widespread use and application today is their cost, poor physical characteristics and variable reproducibility. New cheaper polymers are now coming on the market but their high viscosity, low interfacial tension and low density difference still result in long settling times which make high resolution countercurrent distribution laborious and continuous countercurrent extraction almost impossible.

Immiscible Liquid Affinity Supports

A new class of liquid affinity supports, based on the use of liquid perfluorocarbons, is reported. Macromolecular ligands are controllably substituted with perfluoroalkyl groups prior to addition to the liquid fluorocarbon and emulsification. Such substituted ligands act as efficient surfactants while retaining their biological activity and specificity. The resulting stable emulsions offer many advantages over conventional solid affinity supports, particularly in the area of large scale bioprocessing. High density and deformability of the fluorocarbon droplets allow processing of debris containing samples. In addition, packed emulsions can be easily pumped, thus offering the potential of continuous countercurrent affinity separations. Recovery or concentration of the ligand or its complex is possible by evaporation of the fluorocarbon support.