The construction of DNA molecules of figure-eight structure.

Using DNA molecules to construct a structural scaffold for nanotechnology is largely accepted. In this article, we report on two methods for constructing a figure-eight structure of DNA molecules having a relatively high yield that could be used further as a scaffold for nanotechnology applications. In the first method, two plasmids were constructed that, on digestion with a restriction endonuclease producing nicks in the corresponding sites and after heating, produced complementary single-stranded sequences, enabling the plasmids to hybridize to each other and forming a figure-eight structure. The formation of the figure-eight structure was analyzed by restriction analysis and gel electrophoresis as well as by atomic force microscopy. The second method makes use of the bacteriophage M13 that is obtained as either a single- or double-stranded circular DNA molecule. Two M13 molecules harboring complementary sequences were constructed and produced a figure-eight structure on hybridization. The methods described here could be used further for the construction of nanoelectronic devices.