Page URL:

Drawing with DNA: genetic code makes complex shapes

6 June 2012
Appeared in BioNews 659

Scientists have developed a way of crafting DNA into complex shapes such as letters of the alphabet, symbols and even smiley faces. The nanotechnology may one day be able to create customised DNA structures that can carry therapeutic drugs to specific sites in the human body without triggering an immune response.

The research, published in Nature, builds on a previous concept called DNA origami in which long stretches of single-stranded DNA are folded into 3D structures and held in place using short DNA 'pins'. It was hoped that this technique could create customised carriers capable of shuttling drugs around the body. However, the long DNA strands were taken from a virus and therefore structures created using this method are likely to be attacked by the body's immune system.

Scientists from Harvard University in the US may have got around this by developing a technique that uses synthetic DNA. Their shape-building method involves the creation of a set of building blocks – or 'tiles' - that are carefully selected to build specific shapes.

Each tile comprises a single DNA strand of just 42 letters designed to fold into a specific shape. A tile can connect to four neighbouring tiles as long as they share enough similarities in their DNA sequences. Five interconnecting tiles form a 'pixel' with the final customised structure made of up to 310 pixels. Once a library of unique tiles has been synthesised, an indeterminate number of shapes can be made simply by leaving different tiles out.

'Each tile acts like a Lego block', explained Dr Peng Yin, the lead scientist on the project. 'Once you have a pre-synthesised library, you don't need any new DNA designs. You just pick your molecules'.

Each tile measures just seven by three nanometres (a nanometre is one billionth of a metre) and construction of the final structures requires the help of a specially-designed robot. The desired shape is drawn onto a graphical interface and the robot selects and mixes the strands to create the shape, a process that takes about an hour. To demonstrate the technique, the scientists re-created well known shapes including alphabet letters and smiley faces.

The technology is in its early stages and Dr Yin stresses that 'any technological applications are highly speculative'. He did acknowledge, however, that the synthetic DNA structures 'could be made to be highly biocompatible'.

Dr Paul Rothemund, who invented the original DNA Origami method at the California Institute of Technology, said of this new research: '[These] findings remind us that we are still just apprentice DNA carpenters, and will embolden others to mix hundreds of DNA strands together against prevailing wisdom. The results will probably surprise us'.

Complex shapes self-assembled from single-stranded DNA tiles
Nature |  30 May 2012
DNA drawing with an old twist
Nature News |  30 May 2012
DNA origami: synthetic tiles can make over 100 shapes
New Scientist |  30 May 2012
DNA strands create tiniest Smileys
IOL Science |  31 May 2012
The living ABC: Scientists create tiny alphabet out of DNA - and say 'blocks' could be used to deliver drugs inside human body
Daily Mail |  31 May 2012
19 February 2018 - by Dr Molly Godfrey 
Nanorobots made of DNA, that can target and kill tumours in mouse cancer models, have been developed by scientists...
16 December 2013 - by Chris Baldacci 
Researchers in Germany have discovered a novel way to influence the direction of travel of sperm...
18 November 2013 - by Dr Naqash Raja 
A system that allows researchers to control a tiny cellular transport network has been developed by researchers at the Universities of Oxford and Warwick...
15 October 2012 - by Dr Lucy Spain 
Using blue light as the trigger, scientists have developed a laboratory technique to control where and when genes are expressed within cells...
23 April 2012 - by Ana Pallesen 
Six new kinds of artificial genetic material have been created by scientists. These XNAs, or xeno-nucleic acids, have similar life-building properties to naturally-occurring DNA...
2 April 2012 - by Dr Louisa Petchey 
Synthetic biology, which uses genetic engineering to build new genomes and organisms, has come under attack in a report published by Friends of the Earth and supported by over 100 other 'public interest' groups...
12 March 2012 - by Dr Zara Mahmoud 
A bout of intense exercise can change the way your genes are regulated, scientists have shown. These changes led to an increase in enzymes that are involved in energy production...
7 February 2011 - by Dr Marianne Kennedy 
Genetics is creating more confusion than the offside rule in pub conversation. Most of us had limited teaching on the subject at school or we may have left before Watson and Crick ran out of the pub that night with the structure of DNA on a beer mat. We are left to soak in the media murkiness and skewed views of individuals, which could one day influence important decisions on our health....
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.