Improvement on the visualization of cytoskeletal structures of protozoan parasites using high-resolution field emission scanning electron microscopy (FESEM)

We are using the term "Industrial Polymers" to refer to polymers [plastics] that are produced by the ton or (in the case of films) by the mile. For example, in descending order of world-wide use (tonnage), the top eight of these polymers are polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), styrene polymers (including polystyrene - PS, and acrylonitrile-butadienestyrene/ styrene-acrylonitrile - ABS/SAN), polyesters (PETP), polyurethane (PU), phenolics and aminoplastics.Industrial polymers, which have been produced by the millions of tons for the last five decades and are of obvious social and economic importance, have been exhaustively characterized. Structural features which affect physical properties and indicate process variables have been studied by many techniques other than microscopy (x-ray diffraction, thermal analysis, rheology, chromatographies, etc.). Microscopy techniques for polymer characterization have been well documented. Our motivation to apply field emission (high resolution) scanning electron microscopy to the study of polymers is: (1) The application of low voltage, high resolution SEM to biological materials is well characterized.

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Structural Evidence for Actin-like Filaments in Toxoplasma gondii Using High-Resolution Low-Voltage Field Emission Scanning Electron Microscopy

Microscopy and Microanalysis ◽

10.1017/s1431927603030095 ◽

2003 ◽

Vol 9 (4) ◽

pp. 330-335 ◽

Cited By ~ 23

Author(s):

Heide Schatten ◽

L. David Sibley ◽

Hans Ris

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

High Resolution ◽

Toxoplasma Gondii ◽

Field Emission ◽

Low Voltage ◽

Protozoan Parasite ◽

Cytoskeletal Network ◽

Unicellular Organisms ◽

Scanning Electron

The protozoan parasite Toxoplasma gondii is representative of a large group of parasites within the phylum Apicomplexa, which share a highly unusual motility system that is crucial for locomotion and active host cell invasion. Despite the importance of motility in the pathology of these unicellular organisms, the motor mechanisms for locomotion remain uncertain, largely because only limited data exist about composition and organization of the cytoskeleton. By using cytoskeleton stabilizing protocols on membrane-extracted parasites and novel imaging with high-resolution low-voltage field emission scanning electron microscopy (LVFESEM), we were able to visualize for the first time a network of actin-sized filaments just below the cell membrane. A complex cytoskeletal network remained after removing the actin-sized fibers with cytochalasin D, revealing longitudinally arranged, subpellicular microtubules and intermediate-sized fibers of 10 nm, which, in stereo images, are seen both above and below the microtubules. These approaches open new possibilities to characterize more fully the largely unexplored and unconventional cytoskeletal motility complex in apicomplexan parasites.

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High-Resolution Field Emission Scanning Electron Microscopy (FESEM) Imaging of Cellulose Microfibril Organization in Plant Primary Cell Walls

Microscopy and Microanalysis ◽

10.1017/s143192761701251x ◽

2017 ◽

Vol 23 (5) ◽

pp. 1048-1054 ◽

Cited By ~ 13

Author(s):

Yunzhen Zheng ◽

Daniel J. Cosgrove ◽

Gang Ning

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Cell Wall ◽

High Resolution ◽

Field Emission ◽

Cell Walls ◽

Cellulose Microfibrils ◽

Critical Point Drying ◽

Sputter Coating ◽

Scanning Electron

AbstractWe have used field emission scanning electron microscopy (FESEM) to study the high-resolution organization of cellulose microfibrils in onion epidermal cell walls. We frequently found that conventional “rule of thumb” conditions for imaging of biological samples did not yield high-resolution images of cellulose organization and often resulted in artifacts or distortions of cell wall structure. Here we detail our method of one-step fixation and dehydration with 100% ethanol, followed by critical point drying, ultrathin iridium (Ir) sputter coating (3 s), and FESEM imaging at a moderate accelerating voltage (10 kV) with an In-lens detector. We compare results obtained with our improved protocol with images obtained with samples processed by conventional aldehyde fixation, graded dehydration, sputter coating with Au, Au/Pd, or carbon, and low-voltage FESEM imaging. The results demonstrated that our protocol is simpler, causes little artifact, and is more suitable for high-resolution imaging of cell wall cellulose microfibrils whereas such imaging is very challenging by conventional methods.

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High-resolution scanning electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100127244 ◽

1987 ◽

Vol 45 ◽

pp. 530-533

Author(s):

T. Nagatani

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

High Resolution ◽

Field Emission ◽

Scanning Transmission Electron Microscope ◽

Objective Lens ◽

Second Development ◽

Transmission Electron ◽

Scanning Transmission ◽

Scanning Electron

Although the main development of scanning electron microscopy (SEM) has been accomplished mostly by the Cambridge group and it has not been changed so much for about two decades, it should be noted that there have been two important developments to pursuing high resolution of better than 1nm.Most notably, use of a field emission gun developed by Crewe et al for the scanning transmission electron microscope (STEM) to form a fine electron beam has been most effective in SEMs due to its high brightness and low energy spread. Thus, several models of field emission (FE) SEMs have been developed in the early ’70s and commercialized with a resolution of 2∼3nm at around 30kV.The second development is to use a highly excited objective lens. The specimen has to be set inside the pole-pieces (so-called “in-lens” type).

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