Molecular structure of DNA by scanning tunneling microscopy.
Uncoated DNA molecules marked with an activated tris(l-aziridinyl) phosphine oxide (TAPO) solution were deposited on gold substrates and imaged in air with the use of a high-resolution scanning tunneling microscope (STM). Constant-current and gap-modulated STM images show clear evidence of the helicity of the DNA structure: pitch periodicity ranges from 25 to 35 angstroms, whereas the average diameter is 20 angstroms. Molecular structure within a single helix turn was also observed.
Instituto di Struttura della Materia del Consiglio Nazionale delle Ricerche, Frascati, Italy.
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Felici
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Chiarotti
D004247:DNA / Q000648:ultrastructure*; D004270:DNA, Circular / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D009690:Nucleic Acid Conformation
D004270:DNA, Circular; D004247:DNA