DNA origami

DNA origami are self-assembling biochemical structures that are made up of two types of DNA. To make DNA origami, researchers begin with a biologically derived strand of DNA called the scaffold strand. Then they design customized synthetic strands of DNA, called staple strands. Each staple strand is made up of a specific sequence designed to pair with specific subsequences on the scaffold strand.

Staple strands are introduced into a solution containing the scaffold strand, and the solution is then heated and cooled. During this process, each staple strand attaches to specific sections of the scaffold strand, pulling those sections together and folding the scaffold strand into a specific shape organised by the intrinsic chemical properties of the DNA sequences.

These structures are not just interesting and funny ways for scientists to kill time although the ones shown in the image on the right look indeed funny. Potential applications range from biomedical research to nanoelectronics. Examples include enzyme immobilization, drug carry capsules, and nanotechnological self-assembly of materials. They have also been discussed as active structures for nanorobotic applications such as molecular walkers (artificial molecular motor) on origami and switches for algorithmic computing.

So far DNA origami has been limited to a scaffold strand that is made up some 7,200 bases, creating structures that measure about 70 nm by 90 nm, though the shapes may vary. Researchers from North Carolina State University, Duke University and the University of Copenhagen have now created the world's largest DNA origami. They developed a custom scaffold strand that contained 51 kilobases which resulted in a structure measuring approximately 200 nm by 300 nm.

They also implemented a method to decrease the cost of origami production by improving the chip synthesis platform. The researchers did this by using what is essentially a converted inkjet printer to synthesize DNA directly onto a plastic chip.

Pretty cool stuff.