Challenges:
Small scale has advantages of faster output of population linked traits, faster growth rates in general, reduced sample and reagent requirements. Great! But, as with all systems, this benefit comes with some design challenges and constraints.
Current Ideas:
We are currently working on three models for this step of the pipeline:
Small scale has advantages of faster output of population linked traits, faster growth rates in general, reduced sample and reagent requirements. Great! But, as with all systems, this benefit comes with some design challenges and constraints.
- Biofilm formation. We need the cells to stay suspended so that the cells can move to downstream processing, so that the cells are all subject to the same growth conditions, and so that lysing solutions can effectively reach the cell membranes.
- Gas Exchange. In macrosystems, we use shakers, stirrers, and bubblers which induce turbulence, mixing of gases and nutrients in the broth. Turbulence is limited in microfluidic systems due to physics (see blog).
- Measuring OD and other growth markers: Often in virulence systems, the virulence gene pathway is regulated by a density dependant promoter. The ability to monitor the density of the culture and other parameters are other useful features that could be included in this module of the device.
Current Ideas:
We are currently working on three models for this step of the pipeline:
- Serpentine culture chamber: The culture is constantly moving through the channel to prevent clogging due to biofilm formation. Flow can be induced by a dielectric or as a side feature of impedance measuring ( which uses Voltage like electrophoresis). As the fluid is forced through tight turns, turbulence is induced.
- Magnetic beads: Just like stirbars on the macroscale, magnetic beads can improve gas exchange due to an electromagnetic or magnetic force. They can also assist in downsteam mRNA isolation.
- OpenDrop: Was developed as an Open Source platform towards Digital Biology by the German team. OpenDrop is an automated device, of small size, able to control droplets of fluids such that they mix, split or move from one location to another. In combination with additional elements such as sensors, temperature and magnetic bars, OpenDrop can be developed to fully integrate all the procedures needed during a synthetic biology experiment. http://www.bioflux.eu/hardware.html