Abstract
Double-stranded poly(dG)-poly(dC) and triple-stranded poly(dG)-poly(dG)- poly(dC) DNA were deposited on the modified surface of highly oriented pyrolitic graphite (HOPG) and visualized using atomic force microscopy with high-resolution (radius of ∼1 nm) tips. The high resolution attained by this technique enabled us to detect single-stranded regions in double-stranded poly(dG)-poly(dC) and double-stranded and single-stranded regions in poly(dG)-poly(dG)-poly(dC) triplexes, as well as to resolve the helical pitch of the triplex molecules. We could also follow the reaction of G-strand extension in poly(dG)-poly(dC) by the Klenow exo- fragment of DNA polymerase I. This approach to molecular visualization could serve as a useful tool for the investigation of irregular structures in canonical DNA and other biopolymers, as well as studies of the molecular mechanisms of DNA replication and transcription.
Original language | English |
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Article number | 225102 |
Journal | Nanotechnology |
Volume | 18 |
Issue number | 22 |
DOIs | |
State | Published - 6 Jun 2007 |