Synthetic biology attempts to generate biomolecules with new and/or improved activities for use as, say, drugs or fuel. One way of producing new biomolecules involves directed evolution, in which specific functions are selected for, but that has been slow and labor intensive. A faster method comes from Esvelt et al. at Harvard, who have devised a system for directed evolution that is rapid and continuous, cycling through twenty to thirty rounds of selection in a single day without human intervention.
The new system relies on phage, viruses that infect bacteria, and is thus called "phage-assisted continuous evolution"—yielding the apt acronym PACE. In this system, molecules from E. coli flow through an evocatively named "lagoon" filled with phage. Each phage contains a copy of the Gene Of Interest (GOI), the one that will undergo directed evolution.
That picture.. I'm scared..