This 3-D print shows a DNA-based structure designed to test a critical assumption -- that such objects could be realized, as designed, with subnanometer precision.
Credit: Dietz Lab, TU Muenchen
Reality check for DNA nanotechnology: Lowering barriers to DNA-based nanomanufacturing
December 13, 2012
Two major barriers to the advancement of DNA nanotechnology beyond the research lab have been knocked down. This emerging technology employs DNA as a programmable building material for self-assembled, nanometer-scale structures. Researchers led by Prof. Hendrik Dietz of the Technische Universitaet Muenchen (TUM) have removed these obstacles to structural feedback.
Researchers were able to design a wide variety of discrete objects and specify exactly how DNA strands should zip together and fold into the desired shapes. They could show that the resulting nanostructures closely matched the designs. Still lacking, though, was the validation of the assumed subnanometer-scale precise positional control. This has been confirmed for the first time through analysis of a test object designed specifically for the purpose. A technical breakthrough based on advances in fundamental understanding, this demonstration has provided a crucial reality check for DNA nanotechnology.
Atomically precise control
Strands of DNA that will serve as the template, instructions, and building material for a designed object are placed together at a relatively high temperature where they will remain separate; the temperature is gradually lowered, and somewhere along the line the DNA strands zip together to form the desired structures.
Observing this process in unprecedented detail, the Technical University Munich (TUM) researchers discovered that all of the action takes place within a specific and relatively narrow temperature range, which differs depending on the design of the object.
"Besides telling us that complex DNA objects are manufacturable," Dietz says, "these results suggest something we hardly dared to imagine before – that it might be possible to assemble DNA nanodevices in a cell culture or even within a living cell."
Xiao-chen Bai, Thomas G. Martin, Sjors H. W. Scheres, Hendrik Dietz. Cryo-EM structure of a 3D DNA-origami object. Proceedings of the National Academy of Sciences of the USA, Dec. 4, 2012, 109 (49) 20012-20017; on-line in PNAS Early Edition, Nov. 19, 2012.
Jean-Philippe J. Sobczak, Thomas G. Martin, Thomas Gerling, Hendrik Dietz. Rapid folding of DNA into nanoscale shapes at constant temperature. Science, vol. 338, issue 6113, pp. 1458-1461.
Martin Langecker, Vera Arnaut, Thomas G. Martin, Jonathan List, Stephan Renner, Michael Mayer, Hendrik Dietz, and Friedrich C. Simmel. Synthetic lipid membrane channels formed by designed DNA nanostructures. Science, vol. 338, issue 6109, pp. 932-936.