Astonishingly “supercomputers” have existed for millions of years – inside the cells of every living organism. The genetic material of DNA (deoxyribonucleic acid) of every living cell has the potential to perform “calculations”. Some scientists believe that this material may be utilised to form a future generation of computers. What is DNA?
A traditional computer represents information on silicon chips as a series of electrical impulses - zeroes and ones – and manipulates the information by performing mathematical computations with those zeroes and ones, or binary code, to arrive at an answer. – By contrast, a DNA computer represents information as a pattern of molecules in a strand of synthetic DNA. That information is manipulated by subjecting it to precisely designed chemical reactions that may mark the strand, lengthen it or even destroy it.
The technology behind this concept is still in the very early stages of development. It was in 1994 (just some 8 years ago) that Leonard M. Adleman proposed the concept of using DNA to solve complex mathematical problems. Adleman is often referred to as the “inventor of DNA computers”
Still a long way to go….
DNA molecules HAVE ALREADY been harnessed to perform relatively complex mathematical problems. One day DNA might be integrated into a computer chip that could perform calculations many times faster than the most advanced computer known today.
The success of the Adleman DNA computer proves that DNA can indeed be used to calculate complex mathematical problems. HOWEVER, this poses no threat to silicon based computers in terms of speed. The DNA computed a whole array of possible answers extremely quickly, but it then took a lot of time and human-assistance to actually identify the correct answer.
The next step: logic gates…
Logic gates are a vital part of how a computer carries out functions that you command it to do. These gates convert binary code moving through the computer into a series of signals that the computer uses to perform operations. Currently, logic gates interpret input signals from silicon transistors and convert those signals into an output signal that allows the computer to perform complex functions.
DNA logic gates have been developed and are the first step toward creating a computer that has a structure similar to that of an electronic PC. Instead of using electrical signals to perform logical operations, these DNA logic gates rely on DNA code.
They detect fragments of genetic material as input, splice together these fragments and form a single output. For instance, a genetic gate called the "And gate" links two DNA inputs by chemically binding them so they're locked in an end-to-end structure, similar to the way two Lego bricks might be fastened by a third Lego between them. The researchers believe that these logic gates might be combined with DNA microchips to create a breakthrough in DNA computing.
Scientists have taken DNA computing from the free-floating world of the test-tube (Leonard Adleman’s First DNA computer experiment) and anchored it securely to a surface of glass and gold. In so doing, they have taken a small but important step forward in the quest to harness the vast potential of DNA to perform the same tasks that now require silicon and miniature electronic circuits. "Double Click" the below picture to link to the latest advances made using DNA for computation.
DNA computer components -- logic gates and biochips -- will take years to develop into a practical, workable DNA computer. If such a computer is ever built, scientists say that it will be more compact, accurate and efficient than conventional silicon-based computers.