title: Modular multi-level circuits from immobilized DNA-based logic gates.
abstract: One of the fundamental goals of molecular computing is to reproduce the tenets of digital logic, such as component modularity and hierarchical circuit design. An important step toward this goal is the creation of molecular logic gates that can be rationally wired into multi-level circuits. Here we report the design and functional characterization of a complete set of modular DNA-based Boolean logic gates (AND, OR, and AND-NOT) and further demonstrate their wiring into a three-level circuit that exhibits Boolean XOR (exclusive OR) function. The approach is based on solid-supported DNA logic gates that are designed to operate with single-stranded DNA inputs and outputs. Since the solution-phase serves as the communication medium between gates, circuit wiring can be achieved by designating the DNA output of one gate as the input to another. Solid-supported logic gates provide enhanced gate modularity versus solution-phase systems by significantly simplifying the task of choosing appropriate DNA input and output sequences used in the construction of multi-level circuits. The molecular logic gates and circuits reported here were characterized by coupling DNA outputs to a single-input REPORT gate and monitoring the resulting fluorescent output signals.
authors.affiliation: Department of Chemistry, Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, California 92037, USA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Frezza
authors.forename: Scott L
authors.initials: SL
authors.lastname: Cockroft
authors.forename: M Reza
authors.initials: MR
authors.lastname: Ghadiri
mesh_terms: D001483:Base Sequence; D039301:Computers, Molecular; D004247:DNA / Q000737:chemistry* / Q000235:genetics
chemical_list: D004247:DNA