In this hot article Chris Abell, with colleagues from the University of Cambridge and Radboud University Nijmegen, has designed a simple droplet-based microfluidic system capable of encapsulating individual algal cells and incubating them for up to 10 days. This contrasts from previous techniques by allowing the study of the characteristics of individual algal cells, rather than the bulk population over time. It also has the potential to screen large numbers of cells.