Isoelectric focusing method

Abstract

The disclosure is directed to a method and apparatus for isoelectric focusing of fluids. In accordance with the disclosed method, the flow of fluids to be processed is established in a first direction. This flow of fluids is streamlined by providing a plurality of permeable microporous membranes which define generally parallel channels oriented in the first direction. An electrical potential is applied across the streamlined channels of flowing fluid, and isoelectric focusing is achieved on the fluids during the flow thereof since the membranes allow interchange of fluid constituents therebetween while providing the desired streamlining. An approximation of 'plug' type flow is achieved within the streamlined channels; i.e., flow having an approximately uniform cross-sectional characteristic. In the preferred embodiment of the method of the invention, a recirculation path is established for each of the streamlined channels, such that the fluid flowing out of each channel is recirculated back to the beginning of the channel. Preferably, this is achieved by pumping the fluids in each of the recirculation paths, and also providing cooling for the fluids during the recirculation thereof. In this manner, a number of 'passes' are effected to obtain the desired degree of isoelectric focusing. The cooling, which is performed during the recirculation, serves to minimize problems with dissipation of Joule heat during the isoelectric focusing of the fluids in the streamlined channels. Also, in the preferred embodiment of the invention, the first direction is downward such that the streamlined fluids flow under the influence of gravity to permit gravity equilibrium of fluid levels in the channels across the streamlining membranes.