Scanning tunneling microscope images of adenine and thymine at atomic resolution.

摘要: The scanning tunneling microscope has been used to obtain images of DNA that reveal its major and minor grooves the direction helical coiling, but sufficient resolution not yet achieved identify bases. To determine if this technology is capable identifying individual bases, we have examined molecular arrangements adenine thymine attached basal plane highly oriented pyrolytic graphite. Both molecules form organized lattices following deposition on heated Lattice dimensions, structural periodicities, epitaxy with respect graphite determined. Images these at atomic aromatic regions are strongly detected in both while various side-groups well-resolved. These studies provide first evidence microscopy can be discriminate between purines pyramidines.