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Microscopic Analysis Of Dna And Dna-Protein Assembly By Transmission Electron Microscopy, Scanning Tunneling Microscopy And Scanning Force Microscopy, T. Müller-Reichhert, H. Gross
Microscopic Analysis Of Dna And Dna-Protein Assembly By Transmission Electron Microscopy, Scanning Tunneling Microscopy And Scanning Force Microscopy, T. Müller-Reichhert, H. Gross
Scanning Microscopy
To investigate DNA and DNA-protein assembly, nucleic acids were adsorbed to freshly cleaved mica in the presence of magnesium ions. The efficiency of DNA adhesion and the distribution of the molecules on the mica surface were checked by transmission electron microscopy. In addition, various kinds of DNA-protein interactions including DNA wrapping and DNA super-coiling were analyzed using electron microscopy. In parallel, this Mg2+/mica method can be applied (1) to analyze embedded DNA by scanning tunneling microscopy, (2) to visualize freeze-dried, metal coated DNA-protein complexes by tunneling microscopy, and (3) to image DNA or DNA-protein interaction in air or …
Nucleic Acid Detection By In Situ Molecular Immunogold Labeling Procedures, Marc Thiry
Nucleic Acid Detection By In Situ Molecular Immunogold Labeling Procedures, Marc Thiry
Scanning Microscopy
We have recently combined immunogold labeling procedures with molecular biology methods to pinpoint the precise locations of nucleic acids in biological material at the ultrastructural level. These new immunocytological approaches involve the incorporation of labeled nucleotides in the nucleic acids present at the surface of ultrathin sections prior to immunogold labeling. The antibodies used recognize a nucleoside analogue (bromodeoxyuridine) or a hapten (biotin) employed to label nucleotides. Examples of high-resolution detection include DNA or RNA present in different substructures of cell nuclei, and in particular, in adenovirus-induced intranuclear regions of HeLa cells. In addition to being highly sensitive and specific, …
Atomic Force Microscopy Investigation Of Radiation-Induced Dna Double Strand Breaks, D. Pang, G. Popescu, J. Rodgers, B. L. Berman, A. Dritschilo
Atomic Force Microscopy Investigation Of Radiation-Induced Dna Double Strand Breaks, D. Pang, G. Popescu, J. Rodgers, B. L. Berman, A. Dritschilo
Scanning Microscopy
We have used atomic force microscopy (AFM) to study radiation-induced DNA double strand breaks. Double-stranded plasmid DNA was irradiated with 18-MeV electrons in aqueous buffer, using a medical linear accelerator. Doses of 50, 100, 150, and 200 Gy were delivered to DNA samples, and atomic force microscopy was used to measure the length of each DNA fragment. From these measurements, we obtained the average length of the irradiated DNA for each sample and found a linear-quadratic relationship between the average length and radiation dose.
Atomic Force Microscopy Of Dna, Nucleoproteins And Cellular Complexes: The Use Of Functionalized Substrates, Yuri L. Lyubchenko, Robert E. Blankenship, Alexander A. Gall, S. M. Lindsay, Ottavio Thiemann, Larry Simpson, Luda S. Shlyakhtenko
Atomic Force Microscopy Of Dna, Nucleoproteins And Cellular Complexes: The Use Of Functionalized Substrates, Yuri L. Lyubchenko, Robert E. Blankenship, Alexander A. Gall, S. M. Lindsay, Ottavio Thiemann, Larry Simpson, Luda S. Shlyakhtenko
Scanning Microscopy
Progress towards rapid and simple characterization of biomolecular samples by scanning probe microscopy is impeded mainly by limitations of the current approach to sample preparation. We are working on approaches based on chemical functionalization of mica. Treatment of mica with aminopropyltriethoxy silane (APTES) makes the surface positively charged (AP-mica) and able to hold DNA in place for imaging, even in water. We have shown that AP-mica is an appropriate substrate for numerous nucleoprotein complexes as well. The AFM images of the complex of DNA with RecA protein are stable and indicate a structural periodicity for this filament. AP-mica holds strongly …