Valve-based microfluidic device for droplet on-demand operation and static assay

A valve-based microfluidic device was developed for droplet on-demand operation and static assay. Droplet generation with precise and expectant volume, transportation, fusion, and trapping was achieved by integration of microvalves with programed control. Based on this automatic unique function combination, a droplet team was created with a controllable proportion of components. A DNA sample was encapsulated into the aqueous droplets, selectively merged with probe droplet in the desired ratio, well mixed, and then trapped for the static fluorescence assay with a total reagent consumption of no more than 2 mu l. This method would have a powerful potential for biochemical or chemical research. (C) 2010 American Institute of Physics. [doi:10.1063/1.3521283]