Move over Mona Lisa, here comes tic-tac-toe.
It was just about a year ago that Caltech scientists in the laboratory of Lulu Qian, assistant professor of bioengineering, announced they had used a technique known as DNA origami to create tiles that could be designed to self-assemble into larger nanostructures that carry predesigned patterns. They chose to make the world’s smallest version of the iconic Mona Lisa.
The feat was impressive, but the technique had a limitation similar to that of Leonardo da Vinci’s oil paints: Once the image was created, it could not easily be changed.
Now, the Caltech team has made another leap forward with the technology. They have created new tiles that are more dynamic, allowing the researchers to reshape already-built DNA structures. When Caltech’s Paul Rothemund (BS ’94) pioneered DNA origami more than a decade ago, he used the technique to build a smiley face. Qian’s team can now turn that smile into a frown, and then, if they want, turn that frown upside down. And they have gone even further, fashioning a microscopic game of tic-tac-toe in which players place their X’s and O’s by adding special DNA tiles to the board.