Parallel isoelectric focusing II.

A miniature electrophoretic device is developed on the basis of a new isoelectric focusing (IEF) method, namely parallel isoelectric focusing. We report here the theory and the results of operation of a new parallel isoelectric device (PID). The main advantages and limitations of the method are discussed for miniaturization purposes. It is shown that the method guarantees the fast and complete separation of any complex protein mixtures under acceptable conditions, such as voltage source, temperature, size of the device, and separation process duration. It is shown that the main problem of PID miniaturization is the buffer design, and the relation between Immobiline buffer capacity and solution buffer capacity. The main experimental limitation of PID resolution is protein sensitivity to pH changes.