Scientists have made a big advance in building shapes out of the so-called building blocks of life. New techniques can shape DNA—the double-stranded helical molecule that encodes genes—into objects up to 20 times bigger than previously achieved, three separate groups report today. Together, the new approaches can make objects of virtually any shape: 3D doughnuts and dodecahedrons, cubes with teddy bear–shaped cutouts, and even a tiled image of the Mona Lisa. The techniques could someday lead to a bevy of novel devices for electronics, photonics, nanoscale machines, and possibly disease detection.
Scientists have been making shapes out of DNA since the 1980s, and those efforts took off in 2006 with the invention of a folding technique called DNA origami. It starts with a long DNA strand—called a scaffold—that has a precise sequence of the four molecular units, or nucleotides, dubbed A, C, G, and T, with which DNA spells out its genetic code. Researchers match patches of the scaffold to complementary strands of DNA called staples, which latch on to their targets in two separate places. Connecting those patches forces the scaffold to fold into a prescribed shape. A second version of the technology, introduced in 2012, uses only small strands of DNA—but no scaffolds—that assemble into Lego-like bricks that can then be linked together.
Gigadalton-scale shape-programmable DNA assemblies [nature.com] (DOI: 10.1038/nature24651) (DX [doi.org])
Programmable self-assembly of three-dimensional nanostructures from 10,000 unique components [nature.com] (DOI: 10.1038/nature24648) (DX [doi.org])
Fractal assembly of micrometre-scale DNA origami arrays with arbitrary patterns [nature.com] (DOI: 10.1038/nature24655) (DX [doi.org])