High-throughput multiplexed fluorescence-activated droplet sorting

Bioanalysis: microfluidic-sorters to make better choices Droplet-based microfluidics provides new technologies for cell screening by steering cell-containing microdroplets of interest into different channels at the kilohertz frequency. Until now, in conventional microfluidic sorting, droplets are sorted using electric pulses to move them into one of the two channels. Jean–Christophe Baret from the CNRS and University of Bordeaux in France, Valérie Taly from the CNRS and University of Paris Descartes and Tobias Schneider from EPFL in Switzerland have now boosted dielectrophoretic droplet manipulation to allow for multiple selections in a single device. The teams show how emulsified dye-loaded microdroplets are sorted in five different channels depending on fluorescence intensity: a computer algorithm controls the application of electric pulses to direct the droplets into one of the five channels depending on the fluorescence signals. Numerical models unravel the effect of the dielectrophoretic actuation on the droplet trajectories and are now used to predict the sorting conditions for droplet volumes compatible with single-cell encapsulation.