Application of Direct Photographic Photometry to Preparative Electrophoresis

Abstract

THE supporting medium of most preparative methods of electrophoresis includes a solidified gel or porous solid in order to reduce thermal convection¹. A buffer stabilized in the form of a clear solution, without a solid support, would have the advantages of avoiding adsorption effects between the migrating molecule and the solid, and would make it possible to follow the migrating substances by direct photometric procedures². A method of electrophoresis has been described which uses, as a medium, a thin film of buffer solution³. Thermal convection can be effectively controlled by dissolving in the buffer a sufficient quantity of gelling agent to impart a trace of rigidity or thixotropy. Not enough is added to cause a loss of fluid characteristics (that is, to run freely when tilted) or a loss of transparency. The amount of protein that can be separated can be increased for preparative purposes by increasing the thickness of the buffer from that of a thin film to a solution 1 cm. or more. Direct photographic photometry applied to the separation and isolation of serum proteins by this method was accomplished by the following procedure.