文摘
A high fidelity, surface-based method of nucleic acid analysis has been developed based on DNApolymerase extension of primer-template complexes on DNA microchips. The ability of the method todiscriminate against mismatches and provide an almost "digital" signal recommended it for molecularcomputation. A DNA computer with the capability of solving nondeterministic polynomial time (NP)-completeproblems (those whose time-complexity function rises exponentially with the problem size) in polynomialtime using this Arrayed Primer EXtension (APEX) method was experimentally demonstrated. An algorithminvolving extension of surface-bound primer-template complexes, representing solutions and clauses of aBoolean formula, is described for the solution of two-, three-, and four-variable satisfiability (SAT) problems,including a 3SAT, exploiting the theoretical concepts of Lipton. A discussion of the principles of nondeterministiccomputing with APEX is also provided.