Physically Bending DNA


Tiny Machine Uses DNA to Do Its Work

Source: Reuters

April 14, 2000

WASHINGTON (Reuters) - A tiny machine that can physically bend DNA to do its work may be just the first member of a whole generation of microscopic robots, Swiss researchers said on Friday.

They might be used to diagnose medical conditions, read genes or operate microscopic valves for precise drug delivery, the team at IBM Research in Zurich and the University of Basel in Switzerland said.

Writing in the journal Science, they said they found that DNA can be used to bend tiny silicon ``fingers'' that have a thickness of less than one fiftieth of a human hair.

They rigged up a system of these little cantilevers -- anchored at one end and free to bend up and down at the other -- and glued single strands of DNA onto the top.

DNA naturally forms a double helix like a twisted ladder, and when cut apart will naturally try to put itself back together again.

When the researchers put their cantilevers into a solution with the missing halves of the DNA strands, the pairs zipped themselves together and the little cantilevers bent under the force.

The movement could be used to see genetic variations in the DNA, such as a mutation, but could also itself be harnessed to do work, the researchers said.

``This biomechanical technique has the potential to enable fast and cheap biochemical analysis, and could be used for mobile applications,'' Christoph Gerber of IBM Research, who led the study, said in a statement.

He said the same technology could look for active proteins being produced by cells, including those the body produces during disease or after an injury such as a heart attack.

James Gimzewski of IBM Research said the experiment showed that the unique properties of DNA could be put to work in tiny robots.

``We have found a way to get DNA to do the work for us, so we don't need batteries, motors, or the like to operate tiny machines,'' he said.

Such a little device might be used to open a valve, perhaps to deliver drugs in precise doses right where they are needed in the body.

``For instance, we can envision a system to attack cancerous growth -- the release of just the proper doses of chemicals in the appropriate location of the body could be achieved using tiny microcapsules equipped with nano-valves,'' Gimzewski said.

``They could be programmed chemically to open only when they get biochemical signals from a targeted tumor type. This would enable the right therapy at the right place at the right time, with minimized side effects and no invasive surgery.''

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