Updated | Scientists have created the world's smallest copy of the Mona Lisa using something less traditional than oil paintings: DNA.
Researchers working at the California Institute of Technology used DNA nanotechnology, also known as origami DNA, to "paint" Leonardo da Vinci's masterpiece. DNA origami involves folding a single long strand of DNA into a predetermined shape, much like origami paper. As Motherboard noted, this Mona Lisa measures approximately .000028 inches.
A team of scientists working in the laboratory of Caltech assistant professor of bioengineering Lulu Qian has now created a method that allows origami DNA to self-assemble. To really express it, they demonstrated the capabilities of the method through the DNA that originates the Mona Lisa An article describing the work was published online Wednesday in the scientific journal Nature .
"We are excited about the expansion of DNA origami self-assembly," Qian told Newsweek by email, "Because now it is conceivable to build much more sophisticated artificial molecular machines with sizes similar to those of the simplest form of life, a bacterium." [1
While the technique is fun for obvious reasons, this recent breakthrough-DNA that origamis itself-will also be useful for scientists who find it useful to see their work microscopic on a larger scale. A few weeks before this research was published, MIT reported that DNA origami provided a way to mimic the "scaffolding" structure of photosynthesis. Scientists have been struggling to reproduce artificially.
According to Science researchers have been twisting DNA in all sorts of ways since the 1980s. Paul Rothemund, currently a research professor in bioengineering, computer science and mathematics at Caltech, pioneered DNA origami in 2006. According to a Caltech press release, since then he has used it to make works of art as a smiley face of 100 nanometers (a nanometer is one trillionth part of a meter).
Each DNA strand comprises a series of the same four nucleotides: adenine, thymine, guanine and cytosine, commonly abbreviated as A, T, G and C to become in a double chain, nucleotides A must be linked with Ts and Gs with Cs. When a long yarn is combined in a test tube with a number of shorter yarns, the short yarns function as "staples" that help the long yarn to fold over itself in a certain way. Therefore, DNA origami.
For the process to be autonomous, the Caltech team designed software that processes an image, such as the Mona Lisa, and divides it into small individual squares. The next step is to calculate the correct DNA sequence needed to reproduce each square. Lead author Grigory Tikhomirov, a senior postdoctoral scholar in Qian's lab, said in the Caltech press release that they could have done it by giving each tile unique staples around the edges; Think of a puzzle where each piece fits only in one other correct piece.
"[B] ut then we would have to have hundreds of unique edges, which would not only be very difficult to design, but also extremely expensive to synthesize," Tikhomirov said at the launch. "We wanted to use only a small number of different edge staples but still get all the tiles in the right places."
To accomplish this, the team placed each tile together in stages, the way you put together a big puzzle by breaking it into sections and finally gathering those sections.
Researchers call this practice "fractal assembly". Its software tool is available online for the benefit of other molecular scientists. Caltech's statement said it has already been used to draw a "life-size portrait of a bacterium and a portrait of a rooster the size of a bacterium."
Correction: an earlier version of the story said the representation of the origami DNA of the Mona Lisa measured .0024 inches wide. The correct measurement is .000028.