DNA computing started in 1994 when
Leonard M. Adleman, a University of Southern California researcher,
solved a version of a mathematical problem called the “traveling
salesman problem” using DNA in a test tube. The problem is to find
a route that passes through a certain set of cities exactly once,
given the constraint that only certain routes between cities are
possible. This first DNA computer found the solution for a
seven-city version of this problem by simple trial and error, without
using the logic circuits found in traditional microprocessors.
The problem itself is not difficult to
solve -- conventional computers can solve the traveling salesman
problem for thousands of cities. Adleman's achievement was
significant because it demonstrated that computing can be done using
DNA molecules, rather than by electrical circuits.
Three years later, University of
Rochester researchers created simple Boolean logic gates made from
DNA. Logic gates are the basis of modern computers' processing
abilities, and fashioning them from DNA was a major breakthrough.
The development of logic gates opened the doors to sophisticated
DNA-based processors.
In 2002, scientists at the Weizmann
Institute of Science in Israel unveiled a working microprocessor made
not of silicon, but of protein structures and DNA molecules. A year
later, they had engineered a computer made of a single strand of DNA.This amazing device was vanishingly small, since DNA is nothing more
than a large molecule, yet could perform 330 trillion operations per
second (0.33 PFLOPs). Compare this to the (current) world's fastest
supercomputer, the IBM Roadrunner, which can perform about 1.03
PFLOPs.
