Abstract: The invention provides a microfluidic apparatus for performing 2-D biomolecular separations. The microfluidic 2-D device may include first and second planar substrates which include at least a first dimension microchannel extending in a first direction and an array of second dimension microchannels extending in a second direction, preferably, orthogonal to the first dimension. The ends of at least some of the microchannels are in fluid communication with a plurality of reservoirs. The substrates may further include a number of microchannels and reservoirs. The reservoirs are in electrical communication with a plurality of electrodes and voltage power sources. The device enables two dimensional separations of proteins, DNA and other biomolecules. According to another aspect of the invention, an array of tertiary microchannels extending in a third direction may be utilized.

Abstract: The invention provides a method for performing off-line multi-dimensional separation and analysis of a heterogeneous biomolecular sample. The method includes separating the heterogeneous biomolecular sample into a plurality of fractions using an electrophoresis capillary. The plurality of fractions are then deposited onto one or more structures, which keep each of the plurality of fractions separate from one another. The plurality of fractions are then subjected to non-eluting conditions by titrating the at least one of the plurality of fractions to an acidic pH and adding an ion-pairing reagent to the fractions. At least one of the fractions is then introduced into a capillary reversed-phase electrophoresis capillary. The fraction is then separated in the capillary into a plurality of sub-fractions based on hydrophobicity of the sub-fractions. The sub-fractions are then analyzed to determine their constituent molecules.

Abstract: The invention provides a method for performing off-line multi-dimensional separation and analysis of a heterogeneous biomolecular sample. The method includes separating the heterogeneous biomolecular sample into a plurality of fractions using an, at least partially, capillary isotachophoresis mechanism. The plurality of fractions are then transferred to a liquid chromatography apparatus where they are each separated into a plurality of sub-fractions. The sub-fractions are then analyzed to determine their constituent molecules.

Abstract: The invention provides a microfluidic apparatus for performing 2-D biomolecular separations. The microfluidic 2-D device may include first and second planar substrates which include at least a first dimension microchannel extending in a first direction and an array of second dimension microchannels extending in a second direction, preferably, orthogonal to the first dimension. The ends of at least some of the microchannels are in fluid communication with a plurality of reservoirs. The substrates may further include a number of microchannels and reservoirs. The reservoirs are in electrical communication with a plurality of electrodes and voltage power sources. The device enables two dimensional separations of proteins and other biomolecules. According to another aspect of the invention, an isoelectric point based separation is enabled in a first dimension, and a size based separation in a second dimension.