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Atomic force microscopy of DNA-colloidal gold and DNA-protein complexes
SPIE Proceedings
  • Luming Niu, Iowa State University
  • Wen-Ling Shaiu, Iowa State University
  • James Vesenka, Iowa State University
  • Drena D. Larson, Iowa State University
  • Eric R. Henderson, Iowa State University
Document Type
Conference Proceeding
Publication Version
Published Version
Publication Date
Conference Title
Advances in DNA Sequencing Technology
Conference Date
January 17, 1993
(34.0522342, -118.2436849)
The atomic force microscope (AFM)1 is capable of imaging and manipulating nucleic acids in solution and in air29' 13 We are developing methods for random and site-specific labeling of individual DNA molecules to facilitate manipulation of fragments excised in the AFM and for localization of specific DNA domains, such as protein binding sites and origins of replication. One successful method was to incorporate biotinylated nucleotides at random internal locations or specifically at the ends of linearized DNA molecules in vitro. Following complex formation with Snm diameter streptavidin-gold conjugates, chromatographic purification and passive adsorption of the complexes to mica, the biotinylated domains were easily localized in the AFM by virtue of the distinctive size and shape of the streptavidin-gold complex. In many cases unconjugated streptavidin (i.e., lacking gold) was also observed attached to the biotinylated DNA. A second approach to site-specific labeling of DNA for imaging in the AFM was to react DNA with restriction enzymes having sequence-specific binding properties. Like the unconjugated streptavidin-DNA complexes, these enzyme-DNA complexes were visible without attached colloidal gold. Efforts to image DNA labeled in vivo using bromodeoxyuridine (BrdU) and anti-BrdU antibodies are ongoing.

Luming Niu ; Wenling Shaiu ; James Vesenka ; Drena D. Larson ; Eric Henderson; Atomic force microscopy of DNA-colloidal gold and DNA-protein complexes. Proc. SPIE 1891 (1993); doi:10.1117/12.146706.

Copyright 1993 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
Copyright Owner
SPIE--The International Society for Optical Engineering
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Citation Information
Luming Niu, Wen-Ling Shaiu, James Vesenka, Drena D. Larson, et al.. "Atomic force microscopy of DNA-colloidal gold and DNA-protein complexes" Los Angeles, CaliforniaSPIE Proceedings Vol. 1891 (1993) p. 71 - 77
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