Construction of a Genetic Comparator in Escherichia Coli

Construction of biomolecular computing devices has become a hot topic. Although many biomolecular computing devices have been developed, cellular comparators, which play a critical role in facilitating decision-making, are still challenging to create. A comparator requires a computing tool that can determine values based on judging the existence of a signal. It is challenging to find such a computing tool. The clustered regularly interspaced short palindromic repeats/DNase-dead Cpf1 (CRISPR/ddCpf1) system is a novel expressing interference system with high specificity and programmability. In this paper, we have successfully designed, constructed, and tested a genetic comparator in the bacterium Escherichia coli using the CRISPR/ddCpf1 system. The comparator could indicate the maximum value for up to three signals. The comparator may have many potential applications in decision-making tasks, such as biocomputing, biotherapy, bioremediation, and artificial intelligence. In addition, our results provide important insights into the use of the CRISPR/ddCpf1 system to establish complex cellular computing devices.