SDS capillary gel electrophoresis of proteins in microfabricated channels

Analysis of variations in the concentrations or structures of biomolecules (e.g., mRNAs, proteins, peptides, natural products) that occur either natur ally or in response to environmental or genetic perturbations can provide i mportant insight into complex biological processes. Many biological samples are mixtures that require a separation step before quantitation of variati ons in the individual components. Two-dimensional denaturing gel electropho resis has been used very effectively to separate complex mixtures of protei ns, but it is time consuming and requires considerable amounts of sample, M icrochannel-based separations have proven very effective in rapidly separat ing small amounts of nucleic acids; more recently, isoelectric focusing of proteins also has been adapted to the microchannel format. Here, we describ e microchannel-based SDS capillary gel electrophoresis of proteins and demo nstrate the speed and high resolution it provides. This development is an i mportant step toward the miniaturization and integration of multidimensiona l and array separation methods for complex protein mixtures.