Reproducible Imaging and Dissection of Plasmid DNA Under Liquid with the Atomic Force Microscope

Hansma, Helen G.; Vesenka, James; Siegerist, Cristina; Kelderman, G.; Morrett, H.; Sinsheimer, Robert L.; Elings, Virgil B.; Bustamante, Carlos; Hansma, Paul K.

doi:10.1126/science.256.5060.1180

Cited by 509 publications

(303 citation statements)

References 27 publications

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“…Actin filaments and microtubules have been imaged after adsorption to mica, but in this case tapping mode AFM was used to prevent displacement of the sample (Fritz et al, 1995a,b). Tapping mode imaging has also been key to imaging DNA physisorbed to mica (Hansma et al, 1992(Hansma et al, & 1995. These examples document that the preparation technique described here is of general use for all biological scanning probe microscopes.…”

Section: Resultsmentioning

confidence: 92%

Adsorption of Biological Molecules to a Solid Support for Scanning Probe Microscopy

Müller

Amrein

Engel

1997

Journal of Structural Biology

286

204

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Section: Resultsmentioning

confidence: 92%

Adsorption of Biological Molecules to a Solid Support for Scanning Probe Microscopy

Müller

Amrein

Engel

1997

Journal of Structural Biology

286

204

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“…24,25 HS-AFM images of the dissection process of the net-like structure observed on the isolated outer membrane are shown in Fig. 4c and Movie S4.…”

Section: Dynamic Molecular Movement On Living Cellsmentioning

confidence: 99%

Single-Molecule Imaging on Living Bacterial Cell Surface by High-Speed AFM

Yamashita

Taoka

Uchihashi

et al. 2012

Journal of Molecular Biology

118

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Advances in microscopy have contributed to many biologic discoveries. Electron microscopic techniques such as cryo-electron tomography are remarkable tools for imaging the interiors of bacterial cells in the near-native state, whereas optical microscopic techniques such as fluorescence imaging are useful for following the dynamics of specific single molecules in living cells. Neither technique, however, can be used to visualize the structural dynamics of a single molecule at high resolution in living cells.In the present study, we used high-speed atomic force microscopy (HS-AFM) to image the molecular dynamics of living bacterial cell surfaces. HS-AFM visualizes the dynamic molecular processes of isolated proteins at sub-molecular resolution without the need for complicated sample preparation. In the present study, magnetotactic bacterial cells were anchored in liquid medium on substrate modified by poly-L-lysine and glutaraldehyde. High-resolution HS-AFM images of live cell surfaces showed that the bacterial outer membrane was covered with a net-like structure comprising holes and the hole rims framing them. Furthermore, HS-AFM captured the dynamic movement of the surface ultrastructure, showing that the holes in the net-like structure slowly diffused in the cell surface. Nano-dissection revealed that porin trimers constitute the net-like structure. Here, we report for the first time the direct observation of dynamic molecular architectures on a live cell surface using HS-AFM.

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“…The possible applications range from the fabrication, preparation or modification of nanoscale devices and structures to the characterization, and handling of biological samples, i.e., dissection of DNA, etc. (Fotiadis et al 2002;Hansma et al 1992).…”

Section: Introductionmentioning

confidence: 99%

Atomic force microscope manipulation of multiwalled and single walled carbon nanotubes with reflux and ultrasonic treatments

et al. 2012

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We are reporting the atomic force microscope (AFM) nanomanipulation of ultrasonically dispersed and reflux-oxidized multiwalled carbon nanotubes (MWCNT) and single walled carbon nanotubes (SWCNT) by controlling the AFM tip with a NanoManipulator on a silicon substrate. The structure and the morphology of the carbon nanotubes (CNT) were confirmed with AFM interfaced with NanoManipulator and transmission electron microscope. The modifying parameter, which controls the force exerted by AFM tip, was set to be 0.5 nA in each case (0.5 nA = 20 nN). Bending was observed in ultrasonically dispersed MWCNTs, whereas, cutting was observed for reflux-oxidized MWCNTs along with the lateral movements. Similar observations were found for SWCNTs with sharp cuts and lateral displacements. The results show that CNTs deform by combining bending and distortion when subjected to large mechanical forces exerted by the tip of the AFM. The magnitude of the force, required to deform the reflux-oxidized CNTs is less than that for the ultrasonically dispersed CNTs, for both MWCNTs and SWCNTs.

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Reproducible Imaging and Dissection of Plasmid DNA Under Liquid with the Atomic Force Microscope

Cited by 509 publications

References 27 publications

Adsorption of Biological Molecules to a Solid Support for Scanning Probe Microscopy

Adsorption of Biological Molecules to a Solid Support for Scanning Probe Microscopy

Single-Molecule Imaging on Living Bacterial Cell Surface by High-Speed AFM

Atomic force microscope manipulation of multiwalled and single walled carbon nanotubes with reflux and ultrasonic treatments

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