Success of the Adleman DNA computer

             The success of the Adleman DNA computer proves that DNA can be used to calculate complex mathematical issues. However, this early DNA computer is far from challenging silicon-based computers in terms of speed. The Adleman DNA computer created a group of feasible answers very quickly, but it took days for Adleman to narrow down the possibilities. Another drawback of his DNA computer is that it requires human assistance. The objective of the DNA computing field is to generate a device that can work independent of human involvement.

Years after Adleman's experiment, researchers at the University of Rochester developed logic gates made of DNA. Logic gates are a vital part of how your computer carries out functions that you command it to do. These gates convert binary code moving through the computer in to a series of signals that the computer makes use of to perform operations. Currently, logic gates interpret input signals from silicon transistors, and convert those signals in to an output signal that allows the computer to perform complex functions.

The Rochester team's DNA logic gates are the first step toward making a computer that has a structure similar to that of an electronic PC. In lieu of using electrical signals to perform logical operations, these DNA logic gates depend on DNA code. They detect fragments of genetic material as input, splice together these fragments and form a single output. For example, a genetic gate called the "And gate" links DNA inputs by chemically binding them so they are locked in an end-to-end structure, similar to the way Legos might be fastened by a third Lego between them. The researchers think that these logic gates might be combined with DNA microchips to generate a breakthrough in DNA computing.

DNA computer parts -- logic gates and biochips -- will take years to create in to a practical, workable DNA computer. If such a computer is ever built, scientists say that it will be more compact, correct and efficient than conventional computers. In the next section, we'll look at how DNA computers could surpass their silicon-based predecessors, and what tasks these computers would perform.