Test tube holds a trillion computers

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Hi All,

 

Don't know if this is really good news.................

 

http://news.bbc.co.uk/hi/english/sci/tech/newsid_1668000/1668415.stm

Wednesday, 21 November, 2001, 19:01 GMT

Test tube holds a trillion computers

By BBC News Online's Ivan Noble

 

A computer so small that a trillion of its kind fit into a test tube has been

developed by researchers at the Weizmann

Institute in Israel. Today it is limited to processing DNA which is

synthetically designed. In the future it could

process any DNA molecules.

 

The nanocomputer consists of DNA and DNA-processing enzymes, both dissolved in a

liquid held in a test tube. The

inventors believe it could ultimately lead to a device capable of processing DNA

inside the human body, finding

abnormalities and creating healing drugs. In the medium term it could be turned

into a tool capable of speeding up the

currently labour intensive job of DNA sequencing.

 

DNA sequencing is part of the task of cracking the genetic code of interesting

organisms as diverse as the pneumonia

bug, the tomato and the human body to discover more about the way they function.

Professor Ehud Shapiro, head of the

Weizmann team, says the DNA computer is an automaton, completing its work

without human intervention at each stage of

processing. " Today it is limited to processing DNA which is synthetically

designed. In the future it could process any

DNA molecules, " he told BBC News Online.

 

The machine's input, output and software program are all DNA molecules. The

Israeli team reads the output of the

computer by running the liquid through an electrophoretic gel - the same process

which produces the characteristic black

and white bands of a DNA fingerprint.

 

DNA computing took a leap forwards in 1994 when Leonard Adleman of the

University of Southern California used DNA to

solve a problem commonly known as the travelling salesman problem.

 

This problem sets the goal of working out the fastest way of visiting a given

set of destinations. Prof Adleman,

co-inventor of the RSA encryption scheme which protects most secure transactions

on the internet today, was exploiting

the advantages of DNA computing over conventional silicon.

 

DNA stores a massive amount of data in a small space. Its effective density is

roughly 100,000 times greater than

modern hard disks. And while a desktop PC concentrates on doing one task at a

time very quickly, billions of DNA

molecules in a jar will attack the same problem billions of times over.

 

Prof Shapiro and his team have taken a different approach. Their goal was not

to harness the power of biological

computing to solve weighty mathematical problems, but to build a nanoscale

computer which takes naturally-occuring

information-bearing biological molecules such as DNA as an input. Their success

in creating a nanomachine that works on

synthetically produced short DNA strands is a huge step towards this goal.

 

DNA computing research was inspired by the similarity between the way DNA works

and the operation of a theoretical

device known as a Turing machine and named after the British mathematician Alan

Turing. " Turing machines process

information and store them as a sequence, or list of symbols, which is very

naturally related to the way biological

machinery works, " Prof Shapiro said. The nanomachine devised by his team is a

special case of the Turing machine: a

two-state, two-symbol automaton. It distinguishes between two symbols, like

the zeroes and ones of a conventional

electronic computer.

 

The Israeli team's DNA computer is described in more detail in the journal

Nature.

 

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