The importance of being modular

Abstract

DNA is the material of choice for making custom-designed, nanoscale shapes and patterns through self-assembly. A new technique revisits old ideas to enable the rapid prototyping of more than 100 such DNA shapes. See Letter p.623 Programmed DNA self-assembly is widely used to create nanometre-sized structures. Modular strategies promise simplicity and versatility, yet cannot easily assemble large numbers of small strands into prescribed and complex shapes. Peng Yin and colleagues overcome this problem by designing a molecular canvas: a rectangle assembled from single-stranded tiles each consisting of a short and unique 42-base DNA strand that folds into a 3-nanometre-by-7-nanometre tile and attaches to 4 neighbouring tiles. A desired shape, drawn on the canvas, is produced by simply mixing those strands that correspond to pixels covered by the target shape, and excluding 'off'-pixel strands. With a master strand collection for a 310-pixel canvas, the team then creates more than 100 distinct and complex two-dimensional shapes that establish the method as a simple, modular and robust framework for assembling short synthetic DNA strands into complex DNA nanostructures.