We introduce a new technique to enable label-free detection of charged biomolecules (DNA, proteins) that harnesses a microfluidic on-chip electrode array to generate localized zones where the biomolecules become ultra-concentrated, resulting in formation of a mesophase that is visible under ordinary white light. We illustrate this phenomenon in a series of experiments that involve injecting a dsDNA sample into a microchannel and initiating the focusing and compaction process by applying a 2 V DC potential between a pair of electrodes in the array. The DNA present between the electrode pair migrates toward the anode in response to the electric field and experiences 2-D compaction that confines the biomolecules within a layer at the electrode surface that is only a few microns thick. Consequently, when the electrode is viewed under white light it becomes very bright and is clearly distinguishable. Distinct and colorful textures are also evident when the mesophase is observed under transmitted polarized light using an optically transparent indium tin oxide electrode array. The dramatic magnitude of this effect combined with the extremely low actuation voltages required make this technique a robust label-free method to enable minute sample quantities to be detected in portable bioanalysis systems without the use of chemical fluorophores.