Measuring oscillations
In order to be able to observe oscillations, the device was designed in such a way that it was possible to place it under a microscope for measuring GFP.
Top: Devices under the microscope
Right: Entire setup of the system
By chance an oscillatory behaviour of transfomed E.coli containing the streamlined construct was observed in one of the experiments performed with a plate reader. This suggested oscillations could occur even without applying any flow over the wells. Letting the modeling tool iterate over a range of cell desities while keeping the flow rate constant at 0 confirmed that oscillations could occur at high cell densities. Therefore the measurements for oscillatory behaviour of the construct were taken without applying any flow.
For the experiments, an overnight culture of the cells containing the relevant construct was spun down and resuspended in PBS. The resuspended culture was inoculated in the device and left there to sit for a while. Since the bacteria were bottom fed with LB as seen in the scheme of figure X+2, only the bacteria which settled down in the wells survived, while the bacteria in PBS starved. This is shown in the short video below. The pictures were taken every ten minutes.
Fig.X+2: Applying bottom feeding to get the cells to grow in the wells
First the bacteria float
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