- LONDON (Reuters) - Following
Mother Nature's lead, Israeli scientists have built a DNA computer so tiny
that a trillion of them could fit in a test tube and perform a billion
operations per second with 99.8 percent accuracy.
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- Instead of using figures and formulas to solve a problem,
the microscopic computer's input, output and software are made up of DNA
molecules -- which store and process encoded information in living organisms.
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- Scientists see such DNA computers as future competitors
to for their more conventional cousins because miniaturization is reaching
its limits and DNA has the potential to be much faster than conventional
computers.
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- ``We have built a nanoscale computer made of biomolecules
that is so small you cannot run them one at a time. When a trillion computers
run together they are capable of performing a billion operations,'' Professor
Ehud Shapiro of the Weizmann Institute in Israel told Reuters on Wednesday.
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- It is the first programmable autonomous computing machine
in which the input, output, software and hardware are all made of biomolecules.
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- Although too simple to have any immediate applications
it could form the basis of a DNA computer in the future that could potentially
operate within human cells and act as a monitoring device to detect potentially
disease-causing changes and synthesize drugs to fix them.
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- The model could also form the basis of computers that
could be used to screen DNA libraries in parallel without sequencing each
molecule, which could speed up the acquisition of knowledge about DNA.
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- ENORMOUS POTENTIAL
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- DNA can hold more information in a cubic centimeter than
a trillion CDs. The double helix molecule that contains human genes stores
data on four chemical bases -- known by the letters A, T, C and G -- giving
it massive memory capability that scientists are only just beginning to
tap into.
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- ``The living cell contains incredible molecular machines
that manipulate information-encoding molecules such as DNA and RNA (its
chemical cousin) in ways that are fundamentally very similar to computation,''
said Shapiro, the head of the research team that developed the DNA computer.
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- ``Since we don't know how to effectively modify these
machines or create new ones just yet, the trick is to find naturally existing
machines that, when combined, can be steered to actually compute,'' he
added.
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- Writing in the science journal Nature, Shapiro and his
team describe their DNA computer, which is a molecular model of one of
the simplest computing machines -- the automaton which can answer certain
yes or no questions.
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- Data is represented by pairs of molecules on a strand
of DNA and two naturally occurring enzymes act as the hardware to read,
copy and manipulate the code.
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- When it is all mixed together in the test tube, the software
and hardware operate on the input molecule to create the output.
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- The DNA computer also has a very low energy consumption,
so if it is put inside the cell it would not require much energy to work.
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- DNA computing is a very young branch of science that
started less than a decade ago, when Leonard Adleman of the University
of Southern California pioneered the field by using DNA in a test tube
to solve a mathematical problem.
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- Scientists around the globe are now trying to marry computer
technology and biology by using nature's own design to process information.
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