Hydrogel Discs on Digital Microfluidic Devices for Proteomic Applications

We introduce the use of immobilized enzymes in hydrogels for proteomic sample processing in digital microfluidic systems. In this technique, pre-formed cylindrical agarose discs bearing immobilized enzymes were integrated into digital microfluidic devices bearing arrays of electrodes. In some experiments, fluorogenic enzyme substrates were delivered to gel discs which served as integrated microreactors, in other experiments, droplets bearing proteomic samples were sequentially reduced, alkylated, and digested on gel discs via digital microfluidic droplet operation. We propose that these methods represent a useful new tool for the growing trend towards miniaturization and automation in proteomics and sample processing.