Construction With DNA Bricks

Sometimes science is child’s play, as Peng Yin and coworkers at Harvard University’s Wyss Institute for Biologically Inspired Engineering show in their latest work. They treat DNA like Legos—those beloved plastic interlocking bricks—using short strands of the nucleic acid to construct more than 100 tiny structures, including an itty-bitty model of a space shuttle (Science, DOI: 10.1126/science.1227268). Six months ago, Yin’s team reported a method for using short single strands of DNA to build a canvas from which they could create various shapes such as letters and smiley faces (C&EN, June 4, page 5). The researchers have now expanded the technique into three dimensions. The basic building block is a 32-nucleotide strand of DNA that has four “sticky” regions that can hybridize with four neighboring DNA strands. As the strands assemble, they bend in half, resembling a two-studded Lego brick. They connect with other DNA bricks at 90° angles. Yin’s group uses this method to build one large master structure, roughly 25 nm³, that contains hundreds of bricks, each with a unique DNA sequence. To create more elaborate shapes, such as arches and tunnels, the researchers simply leave out the DNA in specific places.