Previous attempts to use DNA as a molecular building block failed because its double helix structure is so flexible. However, Seeman and colleagues realized that if two synthetic DNA chains were placed side-by-side and linked at two cross over junctions, they would form a very rigid structure - called a DX molecular unit - that would be suitable for building patterns. In their experiments they created an A-B repeating structure of DX molecular units, which was visible as evenly-spaced stripes under an atomic force microscope.

Now that two-dimensional structures have been demonstrated, further development work could result in molecular algorithms suitable for high speed computation, novel photonic materials, biochips and components for molecular electronics.