Experiments and Models of DNA Nano-Catenary Patterns Manipulated by Liquid Flow

Individual DNA molecules were first stretched by a centrifugal force and adsorbed on a modified mica surface. Then, a liquid flow was guided across the surface along a direction perpendicular to the aligned DNA strands. Some nano-catenary-like patterns of DNA molecules were formed, which were revealed by atomic force microscope. A physical mechanism called the “s-suspension bridge” model has been presented, by which the features of the catenary-like patterns of DNA molecules can be understood quantitatively quite well.