Channel to Droplet Sample Extraction and Purification Using Electrowetting Device

To develop advanced ¿channel-to-droplet¿ sample extraction and purification functions on a compact cartridge that is free of sensitive and complex microfluidic components, Core Microsolutions (CMSS) and Professor Sung Cho of the University of Pittsburgh propose to integrate Electrowetting-on-Dielectric (EWOD) droplet handling and in-droplet concentration capabilities with well proven channel-based separation methods to: a) separate target particles, b) extract the concentrated target particles in a mobile droplet, c) bifurcate the particle mix within the droplet using Dielectrophoretic separation methods for a 2nd level of concentration effects, and then d) drive the target-rich droplet to a sensing point or pipette extraction site. This proposed DHS work will develop the sample extraction and purification methods needed to complement CMSS¿ ongoing two year $1M NIH Biodefense Phase I grant that will produce the hardware and driving systems needed for novel bacteria immuno-capture and transduction on an EWOD sensing cartridge. This hybridization of channel and droplet-based sample handling on a generic slide cartridge will enable elegant transfer of channel-based separation products to an array of electronic, optical, surface plasmon resonance (SPR), mass spectrometry (MS) instrumentation. Comparisons in cost/performance will be made against existing methods at the end of Phase I.