From tubes to drops: droplet-based microfluidics for ultrahigh-throughput biology

Droplet-based microfluidics holds enormous potential for transforming the way that many biological screens are performed by affording unprecedented increases in screening throughput and reductions in reagent usage. In this paper, we describe this maturing field and the pioneering work that has laid the foundation for its application to ultrahigh-throughput biological analysis. We begin by introducing the basic elements of the approach and describe the numerous microfluidic components that have been developed for droplet manipulation, with special emphasis on the ones most useful for ultrahigh-throughput analysis. We conclude with a discussion of the first demonstrations of this approach to perform novel, ultrahigh-throughput biological screens.