Now, using a method known as "DNA origami", chemists have managed a similar if much simplified version, creating artificial DNA that can also build itself into larger, more complex structures.
DNA with those capabilities could provide new ways of manufacturing on a small scale – for example, in the field of nanoelectronics – or performing calculations.
The new method has been developed by Paul Rothemund and Erik Winfree, both at the California Institute of Technology in Pasadena.
Now the researchers have shown that such canvases can behave like programmable "seeds" – smaller DNA tiles attach to the seed and the structure snowballs in size to make a structure up to 100 times bigger than the original segment.
To make that happen, the team created two kinds of artificial DNA molecule – a long sequence that folds into the flat "seed" and a number of short sequences that each fold into smaller tiles.
When the two unwound types of DNA undergo cycles of temperature variation between 40 and 90 °C, they fold into seeds and tiles, and then begin to accrete together into the much larger structure. The "growth" process is directed by the sequence of information written into the seed's DNA.
A seed can build a coat for itself out of different types of tiles arranged into a regular pattern. That pattern is then repeated, as the first tile layer coordinates the formation of the second layer into a scaled-up mirror of the original one.
As well as simply scaling up a pattern, sequences can have "counting programs" built into their code that makes it possible for a seed to specify a particular pattern or arrangement after a given number of layers.
"It's sort of like the telephone game [also known as Chinese whispers]," says Winfree.
Anyone that has played that game will know that it doesn't take long for the original message to become distorted. To prevent that, he says, the team has designed the tile DNA sequences to "proof read" their own work and spontaneously reject most erroneous assembly steps.
Advancements in artificial life to our kids is going to be like computers to our parents.