Fig. 2.

Stable communication through a CNF Filter. a Genetic circuit design. In the sender cells on the right side of the trap, an arabinose-inducible promoter drives production of CFP and also LuxI, which enzymatically synthesize AHL. AHL diffuses through the cell membrane and the CNF filter to the left side of the trap, and into the receiving cells, where, together with the constitutively expressed LuxR, it induces the expression of GFP. b Mean fluorescence intensities in the chambers as a function of time for the non-connected and c connected trapping chambers. Blue line, intensity of CFP of the sender cells. Green line, intensity of GFP of the receiver cells. The y axis has a logarithmic scale. d Schematic of a trap with loaded cells. e Phase contrast merged with fluorescent images of the populations in the microfluidic traps during a long-term experiment illustrating stable communication. The sender cells were induced with arabinose after 3 h of growth inside the chambers. In the connected chambers, the receiver population responded to the AHL produced by the sender cells and generated a green fluorescence. In the non-connected chambers, the receiver cells stayed dark as they did not receive AHL. Scale bar, 30 µm