Preparative Electrophoresis on Granular Support Material.

Granular media has been employed as an alternative to paper or gel plates to provide higher loading capacities for preparative electrophoresis. Several materials have been successfully employed for this purpose, which include substances such as cellulose, granular starch, synthetic resins, small glass beads and polyvinyl chloride.

The electrophoresis medium is prepared by making a slurry of the substance selected and pouring the slurry onto a flat plate, suitably delineated with barriers to form and even flat surface in the form of a slab The medium is soaked with buffer and electrodes placed on either side of the slab. The sample is then placed as a band along one face of the slab and a suitable potential applied. Electrophoresis is then allowed to take place for a predetermined time.

A narrow strip of the slab is then taken by slicing the slab along the line of development and the position of the separated substances located by suitable staining or other techniques. Knowing the position of the bands of the separated sample constituents, the strips containing each band are then sliced from the remaining slab and the individual substances extracted and isolated.

The substances of interest are then collected as a solution in the buffer by filtration and then separated from the buffer solution by extraction or other suitable isolation techniques. This type of separation is suitable for collecting samples of a few micrograms up to perhaps, a few milligrams in mass. This procedure has all the disadvantages of a batch process and is not really suitable for the collection of significant quantities of material for further synthetic work.