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From 2010.igem.org

Week-3

Having decided to make a bioclock which would display time, we started searching for different ways of achieving this goal. We needed a display unit, a counter and another part to measure time. We had below ideas for the different parts.

Display unit:

1)Make use of an array of LEC (Light Emitting Cells) constructed by last years Valencia iGEM team to display the hour numerically.

2)Display different colours for the different hours by using the different colour biobricks from last years Cambridge iGEM team.

After discussion we decided to use the second method to display the time. Later we decided to use fluorescent proteins rather than the colour proteins as the Cambridge biobricks was not a part of the 2010 distribution. However, the fluorescent proteins could very easily be replaced by the colour biobricks.The idea to degrade the reporter (either fluorescence or colour) was to use a protein degradation tag. Hence, over time the reporter would get degraded having displayed the time.

Counter and Measuring time:

1)Using one of the oscillators that had been made earlier in combination with a counter.

2)Novel idea to use the rate of diffusion to measure and count time at the same time by using the spatial placement of the colonies to count the hour.Although this idea was a combination of biology and physical diffusion, we decided to go ahead with this approach due to various considerations.Few of them are given below:

- The idea of being able to have such a complex system on a single agar plate was something new and exciting.

- Being able to use micro-fluid chambers for combining the units was a possibility

After discussion we decided to use the second method to count and measure time.In retrospect this seems a interesting choice as many teams and research groups have tried and built oscillators.However, despite the simplicity of the idea, it has obvious similarities to a Integrated Chip(IC). Being able to do away with connections could allow for the complex systems to interact directly without affecting each others function.

Each of the tasks was divided up among us. Each group searched for literature regarding achieving our goals.