Multiple-fracturing and viewing of the same frozen sample at different depths using a low temperature FESEM

1996 ◽  
Vol 54 ◽  
pp. 820-821
Author(s):  
M.V. Parthasarathy ◽  
C. Daugherty
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Field Emission ◽  
Multiple Fracture ◽  
Precise Control ◽  
Cold Stage ◽  
Different Depths ◽  
Transfer Device

The versatility of Low Temperature Field Emission SEM (LTFESEM) for viewing frozen-hydrated biological specimens, and the high resolutions that can be obtained with such instruments have been well documented. Studies done with LTFESEM have been usually limited to the viewing of small organisms, organs, cells, and organelles, or viewing such specimens after fracturing them.We use a Hitachi 4500 FESEM equipped with a recently developed BAL-TEC SCE 020 cryopreparation/transfer device for our LTFESEM studies. The SCE 020 is similar in design to the older SCU 020 except that instead of having a dedicated stage, the SCE 020 has a detachable cold stage that mounts on to the FESEM stage when needed. Since the SCE 020 has a precisely controlled lock manipulator for transferring the specimen table from the cryopreparation chamber to the cold stage in the FESEM, and also has a motor driven microtome for precise control of specimen fracture, we have explored the feasibility of using the LTFESEM for multiple-fracture studies of the same sample.

Obtaining complementary images with sputter coating and high-vacuum evaporation in an field emission SEM equipped with a cryostage

1991 ◽  
Vol 49 ◽  
pp. 74-75
Author(s):  
William P. Wergin ◽  
Eric F. Erbe ◽  
Deryck J. Mills
Keyword(s):  
Low Temperature ◽  
Field Emission ◽  
High Vacuum ◽  
Vacuum Evaporation ◽  
Yeast Suspension ◽  
Cold Stage ◽  
Sputter Coating ◽  
Transfer Device

An Oxford CT 1500 Cryotrans System was mounted on a Hitachi S-4000 FESEM to perform low temperature manipulations and observations. The sample, consisting of a yeast suspension, was frozen in each of six hinged gold specimen holders, which were clamped onto a complementary freeze-etch specimen cap. The cap was mounted on a precooled modified Oxford holder (Fig. 1), and transferred to the dedicated cryochamber and cryostage where the yeast was fractured, etched and sputter coated with Pt. A second sample, mounted in the same type of gold holders, was frozen, fractured, etched, shadowed with platinum and coated with carbon in a Denton DV-503 high vacuum evaporator equipped with a modified DFE-2 freeze-etch module.1 The standard Oxford specimen transfer device was used to insert the holder through the cryochamber and onto the cold stage in the microscope.

Development of Low-temperature Field Emission Apparatus

2009 ◽  
Vol 52 (2) ◽  
pp. 102-104
Author(s):  
Aya KASHIFUKU ◽  
Manabu YOSHINO ◽  
Katsuyuki FUKUTANI ◽  
Tatsuo OKANO
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Field Emission

Advantages of Low Temperature SEM for Bacterial Studies

1995 ◽  
Vol 53 ◽  
pp. 1070-1071
Author(s):  
Stéphane Roy ◽  
Isabelle Babic ◽  
Alley E. Watada ◽  
William P. Wergin
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Field Emission ◽  
Taxonomic Identification ◽  
Chemical Fixation ◽  
Cold Stage ◽  
Transmission Electron ◽  
Critical Point Drying ◽  
Scanning Electron ◽  
Spinach Leaves

The application of transmission electron microscopy (TEM) has greatly increased our understanding of structure-function relationships in bacteriology. However, to achieve further advancements investigators are seeking preparation procedures that would avoid the artifacts associated with conventional chemical fixation, dehydration and critical point drying or embedding. In our laboratory a field emission scanning electron microscope (SEM) was recently equipped with a cold stage. This combination of techniques, referred to as low temperature (LT) SEM, allowed us to examine frozen, fully hydrated biological specimens. The present investigation images bacteria that were cryofixed for LTSEM observations and then freeze-substituted for TEM observations. In addition an attempt was made to culture the samples that had been cryofixed and observed with LTSEM so that taxonomic identification and further microscopic observations could be made.Bacteria used in this study were isolated from spinach leaves (variety New Jersey). LTSEM observations of cryofixed samples were performed on a Hitachi S-4100 field emission SEM equipped with an Oxford CT-1500HF Cryotrans System.

scholarly journals Use of low-temperature field emission scanning electron microscopy to examine mites

Scanning ◽  
2006 ◽  
Vol 22 (3) ◽  
pp. 145-155 ◽  
Author(s):  
William P. Wergin ◽  
Ronald Ochoa ◽  
Eric F. Erbe ◽  
Charnie Craemer ◽  
Ashok K. Raina
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Temperature Field ◽  
Low Temperature ◽  
Field Emission ◽  
Scanning Electron

Low-temperature field emission system for development of ultracoherent electron beams

2004 ◽  
Vol 75 (10) ◽  
pp. 3091-3096 ◽  
Author(s):  
B. Cho ◽  
T. Ogawa ◽  
T. Ichimura ◽  
T. Ichinokawa ◽  
T. Amakusa ◽  
...  
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Field Emission ◽  
Electron Beams ◽  
Emission System

Examination of Frozen, Hydrated Mites Using Low Temperature Field Emission Scanning Electron Microscopy

2000 ◽  
Vol 6 (S2) ◽  
pp. 874-875 ◽  
Author(s):  
Ronald Ochoa ◽  
Eric F. Erbe ◽  
Jeffery S. Pettis ◽  
William P. Wergin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Temperature Field ◽  
Electron Microscope ◽  
Low Temperature ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Viral Diseases ◽  
Depth Of Field ◽  
Scanning Electron

Mites, the second largest arthropod group after insects, occupy every conceivable terrestrial and aquatic habitat in our environment. They feed on plants, infest food products such as meat, cheese and grains, parasitize invertebrates and vertebrates, and transmit fungal, bacterial, rickettsial and viral diseases. Estimates indicate that as many as 1,000,000 species of mites may exist; however, partly because of their microscopic size, only about 40,000 species have been described and classified. During the last 30 years, researchers have increasingly utilized the greater magnification and depth of field available in a conventional scanning electron microscope (SEM) to supplement descriptions of mites that were historically based on light microscopic observations. In addition, this technique provided a better understanding of the relative positions and functionality of organs and improved attempts to elucidate their biology. However, before mites can be imaged with a conventional SEM, they are typically chemically fixed, dehydrated and/or thoroughly dried.

Generation of electron beams by low–temperature field emission

1987 ◽  
Vol 70 (4) ◽  
pp. 13-23
Author(s):  
Jin-Ichi Matsuda ◽  
Mitsunori Kubo ◽  
Chiharu Iriguchi ◽  
Kazuo Kato ◽  
Tsutimu Yamashita ◽  
...  
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Field Emission ◽  
Electron Beams

High-Vacuum Evaporation and a Cryostage to Observe Fractured Yeast

1988 ◽  
Vol 46 ◽  
pp. 256-257
Author(s):  
William P. Wergin ◽  
Eric F. Erbe ◽  
Eugene L. Vigil
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Standard Specimen ◽  
High Vacuum ◽  
Specimen Holder ◽  
Sputter Coating ◽  
Fresh Frozen ◽  
Gain Access ◽  
Scanning Electron ◽  
Transfer Device

Investigators have long realized the potential advantages of using a low temperature (LT) stage to examine fresh, frozen specimens in a scanning electron microscope (SEM). However, long working distances (W.D.), thick sputter coatings and surface contamination have prevented LTSEM from achieving results comparable to those from TEM freeze etch. To improve results, we recently modified techniques that involve a Hitachi S570 SEM, an Emscope SP2000 Sputter Cryo System and a Denton freeze etch unit. Because investigators have frequently utilized the fractured E face of the plasmalemma of yeast, this tissue was selected as a standard for comparison in the present study.In place of a standard specimen holder, a modified rivet was used to achieve a shorter W.D. (1 to -2 mm) and to gain access to the upper detector. However, the additional height afforded by the rivet, precluded use of the standard shroud on the Emscope specimen transfer device. Consequently, the sample became heavily contaminated (Fig. 1). A removable shroud was devised and used to reduce contamination (Fig. 2), but the specimen lacked clean fractured edges. This result suggested that low vacuum sputter coating was also limiting resolution.

Characteristics and Application of Temperature-Field Emitters

1975 ◽  
Vol 33 ◽  
pp. 144-145
Author(s):  
N. Tamura ◽  
T. Goto ◽  
Y. Harada
Keyword(s):  
Temperature Field ◽  
Electron Microscope ◽  
Field Emission ◽  
Resolving Power ◽  
High Brightness ◽  
Field Emitters ◽  
Emission Electron ◽  
Sufficient Stability ◽  
Scanning Electron ◽  
Illuminating System

On account of its high brightness, the field emission electron source has the advantage that it provides the conventional electron microscope with highly coherent illuminating system and that it directly improves the, resolving power of the scanning electron microscope. The present authors have reported some results obtained with a 100 kV field emission electron microscope.It has been proven, furthermore, that the tungsten emitter as a temperature field emission source can be utilized with a sufficient stability under a modest vacuum of 10-8 ~ 10-9 Torr. The present paper is concerned with an extension of our study on the characteristics of the temperature field emitters.

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