From 2007.igem.org

We have two projects for the summer:

1) A biological timer

  To participate in the iGEM competition, we plan to make a timer from a synthetic genetic circuit. Past iGEM

designs of clocks have been successful, so we decided to build on this idea. Our idea is to fashion a genetically modified network within E. coli cells which is regulated by and input signal, and emits an output, or “off” signal after a given amount of time. The input for the circuit will be a specific amount of arabinose and the output will be fluorescence. The bacteria, which will continually synthesize GFP, will be fed an input signal of arabinose sugar. During consumption of the sugar, the GFP production will be repressed. This hiatus in the fluorescence signifies a timed period. Upon complete consumption of the sugar, the bacteria will once again actively generate GFP, signaling that time is up and the timer is off. The amount of arabinose fed to the cells will determine the amount of time it takes for them to fluoresce.

  This timer device will be created as an individual “machine,” independent of a larger network or device.  We are
curious to discover if construction of such a device is possible before we try to integrate it into a larger
system.  Additionally, we plan to add at least one new BioBrick part to the parts registry for future use.  In June
we began the process of choosing and replicating four different BioBricks necessary for our device.     

2) A biological breathalyzer

  For the second project, an alcohol sensitive gene and GFP will be added to yeast so that the amount of alcohol present can be predicted by the intensity of the fluoresence.