Monday, November 15, 1999 Published at 18:20 GMT
The DNA construction set
The four DNA bases unerringly match up
German scientists have used DNA molecules like "Velcro" to stick together microscopically tiny objects.
So far, cylinders, squares, and tetrahedra have been constructed and the researchers hope that these will act as building blocks for tiny machines in the future.
The work, led by Gunter von Kiedrowski, at the Ruhr University, Bochum, exploits the DNA spiral's unerring ability to match itself up to a partner.
Mix and match
In cell nuclei, the DNA double helix is made of two separate strands bound to each other. The strands are a long series of the four chemical "symbols" which are used to encode life's most basic information.
The two strands exactly match one another meaning that, if they were separated in a complex chemical mixture, they are still able to find each other easily.
Professor von Kiedrowski's team used the DNA spiral's ability to recognise another spiral to complete a set of microscopic building instructions.
They synthesised and separated DNA double helixes and then attached the single strands to building materials, such as gold spheres. Then, in solution, the DNA strands found their partners and bound together the components they carried.
They believe the selectivity provided by the DNA pairing will allow complex objects to be assembled. They even speculate such objects could multiply themselves by bio-chemical methods and might be able to optimise their operation through "artificial" evolution.
The work is published in the journal Angewandte Chemie International Edition.