Gold used in DNA computing

Knowing that humans can think faster than any machine, computer scientists have long wondered if they could ever meld the virtually unlimited informational capacity of biology into the sheer brute power of a machine.

Scientists at the University of Wisconsin have taken the so-called “DNA computing” from the test tube and anchored it to a surface of glass and gold. The research is an important step in the effort to harness the potential of DNA (deoxyribonucleic acid) to perform the same tasks that now require silicon and miniature electronic circuits.

DNA computing uses the property of DNA molecules to store enormous amounts of information. By deploying enzymes and biological catalysts that act like software, these molecules are able to perform operations similar to those performed by a computer. Gold supplies a crucial ingredient to the process, described in a recent issue of the journal Nature, which uses a technique for applying DNA to gold-plated glass. Although the technique for applying the DNA is not new, the University of Wisconsin researchers have developed a novel way of simplifying the repetitive steps that previously were necessary to keep the DNA on the surface, where it can be used for executing computations.

According to Prof. Lloyd Smith, a set of DNA molecules was applied to a small glass plate overlaid with gold. In each experiment, the DNA was configured so that all possible answers to a complex computation were included by exposing the molecules to certain enzymes; the molecules with the wrong answers were weeded out, leaving only the DNA molecules with the right answers.

The experiment is important in the ongoing effort to use DNA in computers because a gram of DNA can hold as much information as a trillion compact discs. Also, in a biochemical reaction taking place in a tiny surface area, hundreds of trillions of DNA molecules can operate together, creating the most powerful supercomputer.

DNA computing relies on patterns of molecules in strands to represent information. Certain enzymes act like software, reading and manipulating the patterns.

While conventional computerization is approaching the limits of miniaturization, DNA computing is not anywhere near its limits as far as size is concerned.

Smith warns that DNA computing is still far from being commercially applied.

— The preceding is an excerpt from Gold News, published by the Gold Institute, based in Washington D.C.