Multidimensional Microfluidics for Mapping Post-Translational Modifications

This Phase II SBIR proposal aims to develop a multidimensional protein separation platform based on polymer microfluidics technology which will be capable of mapping a wide range of post-translational modifications (PTMs) in complex protein samples. The proposed system employs three separation dimensions, namely: IEF, SDS gel electrophoresis, and MALDI-MS. The platform will combine IEF and SDS gel electrophoresis on a single microfluidic chip, with chip-level laser-induced fluorescence detection to record the separated protein positions, and an integrated electrospray ionization tip array to elute separated proteins from the chip onto a MALDI target for MALDI-MS analysis. This detection platform will eliminate the manually-intensive process of running standard 2-D gels, while also eliminating sample dilution associated with traditional 2-D PAGE / MALDI-MS interfacing. Furthermore, the system is designed to provide complete 2-D separations in under 15 min, and full PTM identification via MALDI-MS in under 1 hr, approximately an order of magnitude faster than traditional 2-D PAGE, with greatly improved PTM analysis capabilities in a miniaturized format.