I. Introduction
An example of non-silicon-based computing that has increased in popularity in recent years is DNA computing. DNA computing uses DNA(deoxyribonucleic acid) strands to store information. The DNA molecule itself has several features that make it ideal for use in computations. The most important of these are Watson-Crick complementarity and massive parallelism. These allow an NP-complete problem to be solved in a polynomial number of steps in contrast to a silicon-based computer, which would require an exponential number of steps. Adleman [1] first proposed the idea of using DNA computing to solve the Hamiltonian path problem of size in steps. Lipton [2] solved the second NP-complete problem. Subsequently, several scientists have solved other NP-complete problems [3]–[8].