Electrophoresis apparatus and method

A two-dimensional electrophoresis system comprising

• (a) an electrophoresis plate assembly that defines
• (i) a sample separation cavity bounded by opposing major first and second surfaces, each having a defined width and length, and which are spaced apart by an interfacial distance substantially shorter than said width and length, said cavity having an upper portion, a lower portion, and two lateral portions, said cavity further comprising (1) an electrophoresis region located along the upper portion of the cavity adapted to perform charge and/or size-based electrophoresis in a first dimension along the upper portion, and (2) below the first said electrophoresis region, a second electrophoresis region adapted to perform electrophoresis in a second dimension, which contains a plurality of elongate, substantially parallel separation channels aligned in a direction substantially perpendicular to the first dimension,
• (ii) an elongate sample transport channel that is joined to a sample loading port located at a corner of said upper portion, for introducing a sample into said electrophoresis region, and
• (iii) optionally, one or more fluid passageways positioned along the lower portion of the cavity, for introducing or removing liquid from the cavity,
• (b) electrode means for generating a first voltage potential across the first said electrophoresis region between the loading port and the lateral portion across from the loading port,
• (c) electrode means for generating a second voltage potential between said upper portion and lower portion, and
• (d) occupying said cavity, an aqueous medium that may be the same or different in the first electrophoresis region and the second electrophoresis region, such that the rates of migration of sample components in the second dimension depend on sample properties that are different from the sample properties that determine sample migration rates in the first dimension.