DNA nanostructures in which a single long strand of DNA is folded so that it runs through every double helix. The term is by analogy with the Japanese art of paper folding in which a single sheet of paper is folded, without cuts, to create elaborate three-dimensional shapes. Conceptually, there are two types of DNA origami. In single stranded DNA origami, the structure is formed entirely by a single long strand and the folding is due to interactions of the long strand with itself. In scaffolded DNA origami, the folds are formed by the interaction of a long single strand and hundreds of short DNA strands called “staples”. Single-stranded origami structures have the advantage of being clonable, potentially exponentially reproducible like living things. So far, an almost-single-stranded DNA octahedron with just five staples has been reported. Scaffolded DNA origami structures have been easier to design and synthesize; a half dozen two-dimensional shapes including a star, rectangle, triangle and smiley face, as well as a threedimensional hexagonal tube have been reported. Scaffolded DNA origami structures are easily connected to other nanoscale objects such as carbon nanotubes and proteins, and might be used to organize them into complex nanocircuits or nanofactories.
