A DNA computer is a molecular computer that works biochemically. It "computes" using enzymes that react with DNA strands, causing chain reactions. The chain reactions act as a kind of simultaneous computing or parallel processing, whereby many possible solutions to a given problem can be presented simultaneously with the correct solution being one of the results.
The word "computer" is somewhat misleading in this context, as most people think of a computer today as a machine that can generate word processing, produce spreadsheets, display graphics, cruise the Internet and play MP3 files. However, at its core, it is a collection of electronic impulses working across silicon-based circuitry. Electronic computers store information in binary form, then reassemble and interpret that information in a meaningful way. A DNA computer has the same basic ability to store information and compute solutions, though its methodology is different in that it works off molecular automations, or preset reactions. Its greatest potential benefits might lie in different areas that those of electronic computers.
For example, a DNA computer is a tiny liquid computer — DNA in solution — that could conceivably do such things as monitor the blood in vitro. If a chemical imbalance were detected, the DNA computer might synthesize the needed replacement and release it into the blood to restore equilibrium. It might also eliminate unwanted chemicals by disassembling them at the molecular level, or monitor DNA for anomalies. This type of science is referred to as nanoscience, or nanotechnology, and the DNA computer is essentially a nanocomputer.
The DNA computer is only in its early stages of development. Though rudimentary nanocomputers perform computations, human interaction is still required to separate the correct answer out by ridding the DNA computer solution of all false answers. This is accomplished through a series of chemical steps. However, experts are encouraged by the innate abilities of a DNA computer and see a bright future.
Leonard Adleman, one of the pioneers of the DNA computer, reports that a single gram of dried DNA is capable of storing the same amount of information as could fit on one trillion CDs. This, along with the benefits of parallel processing and the negligible power required, guarantee that the DNA computer, or nanocomputer, will continue to be refined and perfected. When molecular computers become a reality, manipulation of matter at the level of DNA will lead to many breakthroughs in all areas of science, industry, and medicine.