Generating synthetic structures from DNA is the aim of DNA nanotechnology. This new field, which merges biology, physics, chemistry and material science utilizes the capability of the natural DNA-strains' ability for auto assembly.
Professor Alexander Heckel and his student Thorsten Schmidt from the Cluster of Excellence for Macromolecular Complexes at Goethe University have developed two rings of DNA measuring 18nm in size, and interlocked them like links in a chain. This structure is called the catenan. The rings are not fixed formations, but allow environmental conditions to help them pivot. They can be used as parts of molecular machines or motors.
The team has reported in the journal Nano Letters that they developed two C-shaped DNA-fragments. Using molecules as sequence-specific glue for the double helix, the Cs were arranged to create two meeting points pointing the open ends away from each other. Two strands binding to the two ring open fragment ends formed the catenan.
The rings are smaller than the visible light wavelengths making it difficult to view them through a microscope. Schmidt uses a scanning force microscope to view the catenans. This device scans the rings placed on a surface with a fine tip.