Visualizing Green Fluorescent Protein and Fluorescence Associated with a Gold Conjugate in Thin Sections with Correlative Confocal and Electron Microscopy

2004 ◽  
Vol 10 (S02) ◽  
pp. 156-157 ◽  
Author(s):  
Paul. A Sims ◽  
Jeff Hardin

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.

Microscopy ◽  
2019 ◽  
Vol 68 (5) ◽  
pp. 417-421
Author(s):  
Kiminori Toyooka ◽  
Naeko Shinozaki-Narikawa

Abstract Correlative light and electron microscopy (CLEM) enables ultrastructural-level analysis of fluorescence-labeled proteins by combining images obtained from both fluorescence and electron microscopies. A technical challenge with the CLEM method is the effective detection of fluorescence from samples embedded in resins, which generally cause fluorescence decay. To overcome this issue, we developed a method for fluorescence recovery of green fluorescent protein (GFP) in resin-embedded semi-thin sections using commercially available antifade reagents. By applying this method, we successfully obtained CLEM images using field-emission scanning electron microscopy with moderately enhanced GFP signals, demonstrating the efficacy of this simple fluorescence recovery method.


Botany ◽  
2012 ◽  
Vol 90 (12) ◽  
pp. 1229-1236 ◽  
Author(s):  
Roxanna Reyna ◽  
Peter Cooke ◽  
Daniel Grum ◽  
Daniel Cook ◽  
Rebecca Creamer

Poisoning of livestock owing to grazing on locoweeds results in significant economic losses in the western United States. Some Oxytropis spp. locoweeds contain a seed-transmitted endophytic fungus, Undifilum oxytropis, which produces the toxic alkaloid swainsonine. We sought to localize and characterize growth patterns of the fungus within leaves and petioles of Oxytropis lambertii Pursh and Oxytropis sericea Nutt. to help define the types of interactions between the fungus and its hosts. Vegetative hyphae were observed within locoweed tissues using integrated imaging. Topographical images from scanning electron microscopy revealed the presence of the endophyte in the pith tissue of petioles. The fungus was identified between plant cells but did not appear to penetrate host cells. Transmission electron microscopy images of thin sections revealed that hyphae were closely associated with host cell walls. Oxytropis sericea was innoculated with green fluorescent protein-transformed U. oxytropis and observed by confocal microscopy, confirming the presence of the endophyte hyphae in leaves and petioles. The fungus was identified only in the pith of petioles using fluorescence and in the vascular bundle throughout extracellular spaces in leaves. These results revealed no signs of a pathogenic interaction between plant and fungus and support the hypothesis of a mutualistic or commensal relationship.


2003 ◽  
Vol 11 (1) ◽  
pp. 3-4
Author(s):  
Stephen W. Carmichael

Temporal resolution has long been a challenge to microscopists. Certainly, spatial resolution has occupied center stage, but we're all concerned about what happens over time in a biologic system, for example, a cell. Tags such as green fluorescent protein (GFP) have been used with confocal microscopy and other light microscopic techniques to achieve outstanding temporal resolution, but good spatial and temporal resolution have proven to be difficult to achieve simultaneously. This has been accomplished in a remarkable study by Guido Gaietta, Thomas Deerinck, Stephen Adams, James Bouwer, Oded Tour, Dale Laird, Gina Sosinsky, Roger Tsien, and Mark Ellisman, who demonstrated a pulse-chase technique that correlates with both fluorescence and electron microscopy.


2000 ◽  
Vol 6 (S2) ◽  
pp. 324-325
Author(s):  
J. A. Davis ◽  
R. G. Garces ◽  
J.-Y. Diao ◽  
F. P. Ottensmeyer

Energy filtered transmission electron microscopy has the potential to provide high resolution, spatially resolved, atomic and chemical information. However, aberrations generated by the electron spectrometer blur the energy resolution and limit the atomic or molecular distributions that can be studied. Energy absorptions corresponding to the visible light range fall below an energy loss of 5 eV. The selection of electrons that have lost an amount of energy corresponding to chromophore absorption by the sample thus requires a spectrometer with a high energy resolution over the full image plane. A corrected prism-mirror-prism filter that has a resolution of 1.1 eV, sufficient to select these low energy loss electrons, was developed and installed by us in a Zeiss EM902. Its imaging capability was verified for a number of different chromophores. The chromophore currently under study is that of the green fluorescent protein (GFP).


2011 ◽  
Vol 19 (5) ◽  
pp. 8-10
Author(s):  
Stephen W. Carmichael ◽  
Philip Oshel

Localizing specific proteins within cells, tissues, and organisms has been a goal of microscopists for generations. In the early 1990s, a breakthrough was made when a molecule originally derived from a jellyfish was introduced as a probe for fluorescence microscopy. This molecule is green fluorescent protein (GFP), and it has become well known for its usefulness in localizing proteins at the level of the light microscope. It is also well known that electron microscopy (EM) offers far superior spatial resolution over light microscopy, but the application of probes to localize specific proteins has required antibodies conjugated with colloidal metals (such as gold). Delivery of antibodies into the cell commonly requires detergents to permeabilize the cell membrane, which compromises the ultrastructural detail. Another breakthrough was recently published on-line by Xiaokun Shu, Varda Lev-Ram, Thomas Deerinck, Yingchuan Qi, Ericka Ramko, Michael Davidson, Yishi Jin, Mark Ellisman, and Roger Tsien: they have developed a method similar to using GFP for light microscopy, but for specifically tagging proteins at the EM level.


2021 ◽  
Author(s):  
Nadja Groysbeck ◽  
Mariel Donzeau ◽  
Audrey Stoessel ◽  
Anne Marie Haeberlé ◽  
Stéphane Ory ◽  
...  

The advances in the microscopy technology have prompted efforts to improve the reagents required to recognize specific molecules within the intracellular environment. For high-resolution electron microscopy, conjugation of selective binders...


2018 ◽  
Author(s):  
Qing Yao ◽  
Sara J. Weaver ◽  
Jee-Young Mock ◽  
Grant J. Jensen

AbstractIn recent years, solving protein structures by single particle cryogenic electron microscopy (cryoEM) has become a crucial tool in structural biology. While exciting progress is being made towards the visualization of smaller and smaller macromolecules, the median protein size in both eukaryotes and bacteria is still beyond the reach of single particle cryoEM. To overcome this problem, we implemented a platform strategy in which a small protein target was rigidly attached to a large, symmetric base via a selectable adapter. Seven designs were tested. In the best construct, a designed ankyrin repeat protein (DARPin) was rigidly fused to tetrameric rabbit muscle aldolase through a helical linker. The DARPin retained its ability to bind its target, the 27 kDa green fluorescent protein (GFP). We solved the structure of this complex to 3.0 Å resolution overall, with 5 to 8 Å resolution in the GFP region. As flexibility in the DARPin limited the overall resolution of the target, we describe strategies to rigidify this element.Author summarySingle particle cryogenic electron microscopy (cryoEM) is a technique that uses images of purified proteins to determine their atomic structure. Unfortunately, the majority of proteins in the human and bacterial proteomes are too small to be analyzed by cryoEM. Over the years, several groups have suggested the use of a platform to increase the size of small protein targets. The platform is composed of a large protein base and a selectable adapter that binds the target protein. Here we report a platform based on tetrameric rabbit muscle aldolase that is fused to a Designed Ankyrin Repeat Protein (DARPin). Phage display libraries can be used to generate DARPins against target proteins. The residues mutated in a phage display library to generate a DARPin against a new target do not overlap with the DARPin-base fusion in the platform, thus changing the DARPin identity will not disrupt the platform design. The DARPin adapter used here is capable of binding Green Fluorescent Protein (GFP). We report the structure of GFP to 5 to 8 Å local resolution by single particle cryoEM. Our analysis demonstrates that flexibility in the DARPin-aldolase platform prevents us from achieving higher resolution in the GFP region. We suggest changes to the DARPin design to rigidify the DARPin-aldolase platform. This work expands on current platforms and paves a generally applicable way toward structure determination of small proteins by cryoEM.


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