|
Information Operating
Derivative |
Main /
AboutA turbidostat is a feedback controlled continuous culture device that keeps cell density constant. Commercially available turbidostats are not designed with academic research goals (such as long term evolution or synthetic circuit characterization) in mind and as a result tend to be too large and have inflexible proprietary software. We've designed an inexpensive, open source, 3D printable, eight vessel turbidostat that can be constructed with commodity parts and open source circuits. Our design is programmed with an open source extensible Python interface that can used to expand the functionality beyond a standard turbidostat. Presently we are using this device to grow microbes in a constant environment for days to weeks while sending chemical signals to characterize gene circuits in bacteria or yeast. Our collaborators at UW, Rice and UC Berkeley have assembled copies own using our designs with their own modifications. On this website you will find a complete set of resources for constructing your own device. Basic Design and operation The operation of our device is separated into a discrete dilution cycle with an adjustable period (typically one minute). First, the current optical density of each chamber is measured. Then, for each chamber, a user-programmable Python module computes the dilution rate as a function of error between desired OD and actual OD. The dilution rates, which may be different for each chamber, are then sent to the embedded circuitry, which controls the media pump. As new media is added, it is mixed by magnetic stir bars diluting old media, cells, and waste products. When the media level rises to the mouth of the effluent tube waste it is force out by positive pressure provided by an aeration input. |