Fig. 1

GFP recombination assay and observation in microfluidic devices. a An inactive bipartite GFP gene contains different microsatellites. Upon endonuclease induction, a DSB is made within the repeat, processed and repaired to reassemble a functional GFP gene (yellow box). Subsequent downstream processes (blue box) happen until GFP is expressed and cells turn green. b Sketch of the microfluidic device containing 1032 cubic traps (100-μm edge). Yeast cells in suspension (concentration: 5 cells/nL) flow into the microfluidic device and sediment into the wells. c Cells trapped in wells are monitored over 24 h both in bright-field and epifluorescence. The number of cells in each well and their level of GFP fluorescence are monitored using the plugin TrackMate [20] on ImageJ [21]. d Time series of the number of cells and number of GFP+ cells are obtained for one well