Team:HKUSTers

Our logo:The Bauhinia purpurea x variegata at the top-left corner is the floral emblem of Hong Kong; the red sundial on the left represents HKUST, as there is a large sundial in HKUST as a landmark; the Chinese brush style English letters reflect the cultural diversity of Hong Kong as a place where east meets west.

Abstract

Does God play dice with the cell?

~The Randomizer~

Stochastic fluctuation in a cellular context and the lambda-phage bifurcation have been extensively studied. However, from a bottom-up synthetic aspect, we aim to exploit the cellular "noise" to build an E. coli version of a computational device, the "Random Number Generator". One random binary digit can be generated by capturing an initial Polymerase binding event with a pair of mutually exclusive promoters. Reciprocal inhibition using two repressors shall achieve unilateral expression of the "switch", with fluorescence reporters indicating the probability of each alternative occurrence. Balancing the two sets of affinity and kinetic parameters and maintaining a single copy of this synthetic device integrated into the bacterial chromosome shall improve performance. If successful, coupled with other reporters we envision multiple extensions of this "Randomizer", including a Memorizer that utilizes a hierarchy of XOR-calculations to "store" a multi-digit random number, and intriguing pattern generation involving chemical gradients and random "population behavior".

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• We are grateful to the generous sponsorship and support from the Lee Hysan Foundation.