Separation of micromolecules

An apparatus for electrophoretic separation of micromolecules having a molecular mass from about 100 to 5000 Da, comprising:

• (a) an anode buffer compartment and a cathode buffer compartment;
• (b) electrodes positioned in the buffer compartments;
• (c) a first chamber and a second chamber positioned on either side of an ion-permeable separation membrane having a defined molecular mass cut-off, the first chamber and the second chamber being positioned between the anode and the cathode buffer compartments and separated by an ion-permeable restriction membrane positioned on at least one side of the separation membrane, the restriction membrane allowing flow of ions into and out of the compartments and chambers under the influence of an electric field but restrict movement of at least one micromolecule type from the second chamber into the cathode or anode-compartment, wherein at least one membrane is formed as a composite arrangement of at least two materials forming a barrier to substantial movement of water.

The method according to claim 16 or 23, further including the step of selecting a liquid sample containing a micromolecule selected from the group consisting of biotin, Brillian Blue FCF (BB FCF), azorubine, phytoestrogen, digoxigenin, hormones, cytokines, dyes, vitamins, chemicals, neutraceuticals, pharmaceuticals, food diet supplements, and combinations thereof.

The method according to claim 16 or 23, further including the step of selecting a liquid sample from the group consisting of crude extracts, microbial cultures, cell lysates, cellular products, chemical processing mixtures, cell culture media, plant products or extracts.