Nanoporous device for accurate dose control in high throughput screening

This paper reports a new microfluidic high throughput screening(HTS) device targeted for cell based assays. The device consists of a nanoporous membrane, imprinted with poly-dimethylsiloxane (PDMS) to block all pores except in selected areas (microspots) arranged in an array. This membrane is sandwiched between a gel layer above, for cell culture, and a microfiuidic network below, which provides fluidic access to the gel region above the microspots. The nanoporous membrane reduces diffusion significantly while allowing electrophoretic motion. Electrophoretic pumping of model drug candidates into the gel from the microchannels underneath in a controlled manner was demonstrated. Drug spots of 200 mum to 6 mm in diameter on 3 mm thick gel layer were created. Dosing accuracy of 50 mug was achieved.