Electrical separator apparatus and method of counterflow gradient focusing

A preparative scale electrical separator, which is matrix-free and may be operated in both a batch mode and a continuous, flow-through mode is provided. It may be scaled according to the solution quantities which are to be processed. An internal cooling system whereby the process fluid is always in close proximity to a chilled surface assures an efficient heat dissipation during the separation and concentration processes and also allows the use of higher voltage gradients and shorter separation times than prior designs of electrophoretic separators. Electroosmotic and convective mixing is reduced by providing internal, compartmentation of sample fractions, focusing is improved and focusing times are decreased. A counter-flow gradient focusing method using the electrophoretic separator allows for separation of cells from human or animal blood and tissues, cells from plants, bacteria and viruses. The counter-flow gradient focusing method employs both a counter-flow in a direction opposite from the electromobility of the charged components and a flow gradient resulting from the withdrawal of a fractional flow unit from each subcompartment in the apparatus.