Washington iGEM



The Chromastat is an affordable, modular device that can manipulate and analyze cell cultures in real time. The Chromostat is able to manage the expression of genes from the violacein pathway in yeast by adding inducers. We used a Raspberry Pi to create a closed loop control system: when a user inputs a desired color ratio into the interface, the RGB and turbidity sensors in our Chromastat measure the culture’s color and optical density, and the system measures the deviation from the desired ratios, leading our motorized syringe pump system to accurately release the appropriate amount of inducers to correct the deviation and turn on/off the corresponding genes. Furthermore, our closed loop system can be applied to metabolic pathways used in industry right now, such as in bioremediation, ethanol production, and beer brewing. For more information about the design, hardware, software, and other details of our Chromastat, please visit our drylab subpages.


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We built an affordable and modular device called a Chromastat that could autonomously control a cell culture. After many iterations, we designed our device to run a feedback loop that uses our custom-made syringe pump system to modify inputs to the culture.


This year, the UW iGEM team has created the Chromastat: an affordable, modular, and autonomous turbidostat + color detector.


Our software is both easy-to-use and easy to modify. User-friendliness was a high priority - much more so than similar ad hoc scientific tools. By using Oracle standard Java software development idioms and thorough JavaDoc code documentation, we’ve created a codebase that is easily adjustable by anyone with a modicum of Java experience.


By establishing a meaningful relationship between measured RGB values and concentrations of specific metabolites, our Chromastat provides a cheaper and more effective way to monitor and manage cell cultures and their products through the use of our highly precise and affordable motorized syringe pump motor system. Additionally, the Chromastat’s user-friendly design and interface makes it extremely feasible to reproduce and build with provided instructions. With more time, we would like to test the Chromastat with various cell cultures and metabolic pathways other than the violacein pathway to further explore the capabilities of our device. It would be an exciting challenge to figure out ways to adapt the violacein pathway or other color-related pathways to the concentration of different cell culture products.