In the field of synthetic biology, Genetic memory devices have been constructed and applied widely from Biocomputing to biomedical technologies as a crucial component. Such memory devices include a cellular counter; a fundamental device which memorizes the number of induction events. Recent efforts have resulted in a cellular counter that can count up to three events. However, this counter cannot be reset to its initial state. Here, we propose a resettable cellular counter called “sigma recounter”. This counter utilizes the regulation system of sigma factor and anti-sigma factor as the key of its resetting mechanism. In this system a set of sigma factors are designed to update and maintain a count that responds to each inducted event. By the other stimulus, the system initiates a genetic circuit that can express a suitable set of anti-sigma factors and erases the existing memory, which will enable our device to restart the count from any state.
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