There are limits to desktop and supercomputers as eventually there will come a point when electronic miniaturization can go no further as components become smaller and more transistors are embedded onto silicon chips. DNA computing is just one of many new computing techniques already in development. Because DNA is so ubiquitous, it is convenient as well; the four constituent bases of DNA act as “bits” of information comparable to 0 and 1 in binary.
First demonstrated in principle in 1994, DNA techniques were used to solve a Hamiltonian directed-path graph, an important type of problem in mathematics and computer science. Those who haven’t heard of this problem need only to think back to elementary school, where teachers might have presented a puzzle challenge to draw a continuous set of lines through several points on paper without retracing any lines. The logic behind this is that any solution attempts are carried out simultaneously, breaking down larger problems into smaller ones, which can then be solved at the same time.
In the initial demonstrations, each point on the was represented as a 20-unit oligonucleotide (a short segment of the DNA molecule), and allowed moves between any two points were represented as 10 unit complements. Whenever a grand total of oligonucleotides was linked to DNA polymerase (an enzyme that copies DNA), then all possible paths were produced.
