Figure 1.
Schematic representation of the flow device.
A) Schematic representation of the flow device, with the dimensions in mm. Depicted in red and blue are the in- and outflow channels of the top compartment (light green). The respective in- and outflow channels of the lower compartment (yellow) are given in purple and dark green. B) Electron microscopy image of a microsieve. C) Electron microscopy image of a microdish. See File S1 for more views of the device.
Table 1.
Overview of the BioBrick parts used.
Figure 2.
Cell retention on the microsieve.
Retained clusters of fluorescent E. coli cells on the sieve (100x magnification). The diagonal light grey bands are the permeable areas of the microsieve that contain the pores.
Figure 3.
Oscillating GFP expression observed in microdish wells.
Fluorescent E. coli cells in the wells of the microdish showing variations in signal strength over time. The graph depicts variations plotted with the image analysis and processing tool ImageJ. The x-axis represents time, and the y-axis represents fluorescence (in arbitrary units and with a variance of maximally 0.01 for the normalised data of 5 wells). Below the graph are microscopic images of fluorescent bacteria in the cultivation chip wells at different intervals using identical illumination conditions and CCD camera exposure times. The time points at which the images were taken are indicated with an asterisk.
Figure 4.
Co-cultivation of cells separated by a microsieve.
Increase of GFP expression of inducible cells on the sieve after inoculation of inducer cells below. Graph plotted with the image analysis and processing tool ImageJ. The x-axis corresponds to time and the y-axis shows the detected GFP signal (in arbitrary units). Below: a number of representative images of the microsieve. The time points at which the images were taken are indicated with an asterisk.
Figure 5.
Co-cultivation of cells in the flow device.
Expression of GFP increases over time in cells growing in microdish wells after adding inducer (Acyl homoserine lactone (AHL) producing) and RFP expressing cells to the bottom compartment of the flow device. The intensity of the light emitted from five wells was quantified using imageJ and normalized against the background. No RFP was detected in the top chamber, indicating that the inducer-cells added to the bottom chamber did not come in contact with the top, and GFP expression was induced by diffusion of the inducer (AHL) through the microdish.
Figure 6.
Fluorescent nematodes observed in the flow device.
A) Nematodes floating over the wells while the chamber is filled with liquid. The fluorescent oesophagus in the front side of the nematode is clearly visible. B) Nematode trapped in a well filled with fluorescent E. coli cells after removing the liquid from the chamber. C) Next day: A nematode after consuming all fluorescent bacteria from the well, resulting in observable fluorescence in the nematode intestine.