An AFM Study for Stretching Electric Field Induced DNA

An effective method of DNA stretching using electric field on mica surface was proposed for extremely low solu- tion concentration of DNA. DNA stretching based on electric field was observed by AFM and well applied on the concentra- tion range from 57◊10 -3 ng/mL to 57◊10 -6 ng/mL. Stretched DNA existed in the middle of two electrodes. The difference in stretching efficiency for the different surfaces of bare mica, Mg 2+ soaked mica and AP-mica was discussed. The best perfor-