Tech Primer

DNA Computers

What are they all about?

DNA (Deoxyribonucleic Acid) computing is also known as molecular computing. It is the process of driving computation and storing and retrieving data using the structure of DNA molecules. A DNA computer stores information and does complex calculations. Leonard Adleman of the University of Southern California developed DNA computing, and Bernhard Yurke developed the DNA motor. These machines are capable of storing a billion times more data than a conventional PC.

What’s the technology used for?

The technology is not fully developed yet. Conventional computers operate linearly i.e. they tackle one task at a time. DNA computing is similar to parallel computing wherein complex mathematical problems are solved in hours. Problems that a conventional computer would take years to solve are tackled in hours by breaking them into smaller pieces and attacking in parallel.

A DNA computer is basically a collection of specially-selected DNA strands. It does not work on traditional silicon-based technology, but leverages DNA and molecular biology. Right now, the work of making one-dimensional lengths, bi-dimensional tiles and three-dimensional DNA graphs is underway.

Are there any drawbacks?

The goal of DNA computing is to create a device that works independently without any human involvement or intervention. Presently, its major drawback is that it requires human assistance. However, it has several advantages like it can solve complex mathematical problems. DNA is part and parcel of every living thing, making it a cheap source, and a computer built around it is very small and can hold more data. For example, a single gram of DNA, i.e. the size of a half- inch cube, can hold as much data as a trillion CDs. DNA biochips are clean vis-à-vis traditional microprocessors that are toxic. DNA computers are challenging silicon-based computers in terms of speed. In a PC, electrical signals are used to perform logical operations, whereas a DNA computer uses logic gates that rely on DNA codes. The latter’s components are logic gates and biochips, and are still under development and may take years to develop. Once they are developed, they will be more compact, accurate and efficient than conventional computers. The significance of DNA computing is it demonstrates the possible ways through which a problem can be solved—especially a problem that is difficult or impossible to solve with the help of traditional computers.

Who’s conducting research?

Research is being done by NASA’s Jet Propulsion Laboratory, Pasadena, California, and its Ames Research Center, Moffet Field, California, as part of its Computing, Information and Communication Technology Programme.

Will they be used for everyday tasks?

The process of repeatedly tying and bonding DNA strands involves a large amount of molecules. There are a number of fundamental problems which make it unlikely that DNA computers will ever be used for tasks such as word-processing.

For more information visit xtrj.org/ssm6/usc_experiment.htm

—Garima Grover

grover_garima@hotmail.com