DNA 'origami' describes the practice of using specially designed DNA molecules to guide the assembly of nanostructures into a variety of shapes. Now researchers have used DNA origami 'tiles' to form two-dimensional crystals with edges reaching 2–3 micrometres in length. This should allow larger and more complex structures to be created, say Nadrian Seeman and his colleagues at New York University.

The authors used cross-shaped tiles — made from the DNA strands of the M13 virus — with uneven, or 'sticky' ends. Because the axes of the DNA helical strands were perpendicular, the tiles self-assembled in two dimensions to form arrays. This overcomes problems previously encountered with tiles that assembled mainly in one dimension, the authors say.

Angew. Chem. Int. Edn doi:10.1002/anie.201005911 (2010)