Imaging of Single Extended DNA Molecules on Flat (Aminopropyl)triethoxysilane−Mica by Atomic Force Microscopy

Abstract

Long strands of DNA have been deposited, extended, and immobilized on chemically modified mica for study with an atomic force microscope (AFM). By employing a modified “molecular combing” technique and carefully silanized mica, we show that DNA molecules may be distributed uniformly, adsorbed in extended conformations, and bound with great tenacity. When maintained in a buffer solution, these strands remained stable for >5 h. Scanning the surface with high loads applied to an AFM tip induced fragmentation in the strands, but remaining pieces never relinquished their original positions. Further imaging applications, such as after treatment of the DNA by molecular hybridization or DNA synthesis and labeling in situ, are discussed.

[Ru(TAP)3]2+‐Photosensitized DNA Cleavage Studied by Atomic Force Microscopy and Gel Electrophoresis: A Comparative Study

“…Then the substrate was rinsed with 5 mL Milli-Q water and dried with Ar gas. [18] For both modified mica substrates, 10 mL of the plasmid DNA solution (1 mg mL…”

DNA Fiber Mapping Techniques for the Assembly of High-resolution Physical Maps

“…In their studies imaging DNA molecules by atomic force microscopy, Hu et al (1996) let coverslipped DNA molecules bind to the surface for only a few minutes. When the coverslip was removed for imaging, the molecules were straightened by the moving meniscus.…”

Reversible, site‐specific immobilization of polyarginine‐tagged fusion proteins on mica surfaces

“…Fax: +1 (415) 725 6044. E-mail: pwagner@cmgm.stanford.edu Si(A1)O4 tetrahedra has been used as substrate for monolayer formation of amphiphilic organic molecules, such as alkylphosphonic acids [15] and organosilanes [16][17][18][19][20]. Unfortunately, the former are not robust under aqueous conditions and the latter are often isotropically rough with monolayer formation characterized by low reproducibility, especially if terminated with a nucleophilic group in the ~0-position.…”