November 30, 2012
Scientists build with DNA bricks
Researchers at Harvard's Wyss Institute have coaxed single strands of DNA to fit together like Lego bricks and form scores of complex three-dimensional shapes, including a teeny-tiny space shuttle. The technique, described in this week's issue of the journal Science, adds a new dimension to molecular construction and should help open the way for nanoscale medical and electronic devices. "This is a simple, versatile and robust method," the study's senior author, Peng Yin, said in a news release. The method starts with synthetic strands of DNA that take in just 32 nucleotides, or molecular bits of genetic code. These individual "bricks" are coded in a way that they fit together like Lego pegs and holes to form larger shapes of a specific design. A cube built up from 1,000 such bricks (10 by 10 by 10) measures just 25 nanometers in width. That's thousands of times smaller than the diameter of a single human hair.
The latest research builds upon work that the Wyss researchers detailed in May, which involved piecing together DNA strands to create two-dimensional tiles (including cute smiley faces). This time around, the strands were twisted in such a way that they could be interlocked, Lego-style. As any visitor to Legoland knows, such structures can get incredibly complex in the hands of a skilled builder. Yin and his colleagues are still learning their building techniques. Fortunately, the bricks could be programmed to build themselves, with the aid of 3-D modeling software. Once the designs were set, the researchers synthesized strands with the right combinations of nucleotides — adenosine, thymine, cytosine and guanine — so that when they were mixed together in a solution, at least some of the bricks would form the desired design. To demonstrate the method, 102 different 3-D shapes were created using a 1,000-brick template.
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