Electron Microscopy of Antarctic Soils: Visualization of Bound Micro-Organisms

1975 ◽  
Vol 33 ◽  
pp. 642-643
Author(s):  
I. L. Uydess ◽  
C. W. Rice ◽  
W. P. Hempfling
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Saline Solution ◽  
Soil Samples ◽  
Dry Valleys ◽  
Antarctic Soils ◽  
Glass Slides ◽  
Micro Organisms ◽  
Phosphate Buffered Saline

During Professor Wolf Vishniac's final journey to the “Dry Valleys” region of South Victorialand, Antarctica, he and Professor Zeddie Bowen conducted a number of experiments designed to re-examine claims of sterile or “abiotic” soils made by other investigators visiting these same regions. In addition to “labeled-release” experiments in which C14-labeled amino acids were inoculated into the soil, sterile carbon and collodion coated EM grids mounted on glass slides were implanted into the ground at geographically distinct sites. The slides were allowed to incubate in situ for a period of 4-5 weeks during which time the typical diurnal soil temperature ranged between -10° and 0°C. The slides were then carefully collected so as not to disturb attached soil particles and sealed within screw-cap containers filled with a 1.5% glutaraldehyde-phosphate buffered saline solution. Bulk soil samples were also collected aseptically from each station for examination in the laboratory.

Electron Microscopy of Bacterial-Like Microorganisms From the Antarctic Soil

1973 ◽  
Vol 31 ◽  
pp. 568-569
Author(s):  
Ian Uydess ◽  
Wolf Vishniac
Keyword(s):  
Electron Microscopy ◽  
Structural Characteristics ◽  
Uranyl Acetate ◽  
Soil Samples ◽  
Lake Area ◽  
Antarctic Soil ◽  
The Antarctic ◽  
Phosphate Buffered Saline ◽  
Microscopy Examination

Recently, a number of soil samples isolated from geographically distinct regions in the Asgard Range-Vanda Lake area of the Antarctic, were shown to contain living microorganisms which displayed bacterial-like morphologies. The microorganisms isolated from these samples were observed to have heterogeneous structural characteristics ranging from those with “typical” Gram - or Gram + morphologies, to those with “unique” morphologies which may be intermediate to the eubacteria and lower algae.Cell pellets prepared from the various soil samples were rinsed in phosphate buffered saline and fixed in Dalton's Chrome Osmium. These were then post-fixed in aqueous Uranyl Acetate, dehydrated in a graded alcohol series, and then embedded in Epon for electron microscopy. Examination of these preparations revealed the existence of several distinct morphologic types of bacterial-like microorganisms.

scholarly journals Coated Glass Slides TACAS Are Applicable to Heat-Assisted Immunostaining and In Situ Hybridization at the Electron Microscopy Level

2015 ◽  
Vol 48 (5) ◽  
pp. 153-157 ◽  
Author(s):  
Takahiro Matsui ◽  
Takanori Onouchi ◽  
Kazuya Shiogama ◽  
Yasuyoshi Mizutani ◽  
Ken-ichi Inada ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Coated Glass ◽  
Electron Microscopy Level ◽  
Glass Slides

BOUND γ-AMINOBUTYRIC AND OTHER AMINO ACIDS IN BRAIN

1965 ◽  
Vol 43 (3) ◽  
pp. 407-416 ◽  
Author(s):  
K. A. C. Elliott ◽  
R. Tariq Khan ◽  
F. Bilodeau ◽  
R. A. Lovell
Keyword(s):  
Amino Acids ◽  
Calcium Ion ◽  
Saline Solution ◽  
Sucrose Solution ◽  
Particulate Material ◽  
Free Form ◽  
Sucrose Solutions ◽  
Gaba Content ◽  
Saline Medium

Previous work has shown that when brain is homogenized in saline medium, part of the γ-aminobutyric acid (GABA) in the tissue is found in free solution and part is bound or occluded in particulate material. In the present work it is shown that the GABA content of solid brain or anaerobic brain suspensions increases with time and the increase is all in the free form. In suspensions in the presence of oxygen and glucose no increase in GABA occurs. A lower proportion of the GABA is found in bound form if the suspension is prepared in the cold rather than at room or body temperature. The amount found in bound form is sharply dependent on pH. The optimum is about pH 7. If brain is homogenized in plain sucrose solutions, or if potassium is substituted for sodium in saline solution, the amount of bound GABA found is half that found in isosmotic sodium chloride. The normal amount remains bound if 10 mM sodium ion or 5 mM calcium ion is present in the sucrose solution. Glutamic acid, glutamine, alanine, and aspartic and acetylaspartic acids are also partly bound in brain. The amounts of these amino acids as well as of GABA found in brain frozen in situ are considerably lower than in brain which has been excised rapidly after death but without freezing.

Quasi-Two-Dimensional NaCl Crystals Encapsulated Between Graphene Sheets and their Decomposition under the Electron Beam

Nanoscale ◽  
2021 ◽  
Author(s):  
Tibor Lehnert ◽  
Silvan Kretschmer ◽  
Fredrik Bräuer ◽  
Arkady V Krasheninnikov ◽  
Ute Kaiser
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Sodium Chloride ◽  
Saline Solution ◽  
Graphene Sheets ◽  
Two Dimensional ◽  
Transmission Electron ◽  
Aberration Corrected

Quasi-two-dimensional (2D) sodium chloride (NaCl) crystals of various lateral sizes between graphene sheets were manufactured via supersaturation from a saline solution. Aberration-corrected transmission electron microscopy was used for systematic in-situ...

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Immunocytochemistry. A Review of Methodology for Electron Microscopic Applicaiton

1974 ◽  
Vol 32 ◽  
pp. 328-329
Author(s):  
Joseph E. Mazurkiewicz
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Ultrastructural Level ◽  
Electron Microscopic ◽  
Biological Interest ◽  
Investigative Approach ◽  
Immunologic Activity ◽  
Dense Label

Immunocytochemistry is a powerful investigative approach in which one of the most exacting examples of specificity, that of the reaction of an antibody with its antigen, isused to localize tissue and cell specific molecules in situ. Following the introduction of fluorescent labeled antibodies in T950, a large number of molecules of biological interest had been studied with light microscopy, especially antigens involved in the pathogenesis of some diseases. However, with advances in electron microscopy, newer methods were needed which could reveal these reactions at the ultrastructural level. An electron dense label that could be coupled to an antibody without the loss of immunologic activity was desired.

Electron Microscopy of Mycoplasma Pneumoniae

1971 ◽  
Vol 29 ◽  
pp. 258-259 ◽  
Author(s):  
E. S. Boatman ◽  
G. E. Kenny
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Growth Phase ◽  
Hela Cells ◽  
Sulfonic Acid ◽  
Gamma Globulin ◽  
Horse Serum ◽  
Morphological Aspects ◽  
The Family

Information concerning the morphology and replication of organism of the family Mycoplasmataceae remains, despite over 70 years of study, highly controversial. Due to their small size observations by light microscopy have not been rewarding. Furthermore, not only are these organisms extremely pleomorphic but their morphology also changes according to growth phase. This study deals with the morphological aspects of M. pneumoniae strain 3546 in relation to growth, interaction with HeLa cells and possible mechanisms of replication.The organisms were grown aerobically at 37°C in a soy peptone yeast dialysate medium supplemented with 12% gamma-globulin free horse serum. The medium was buffered at pH 7.3 with TES [N-tris (hyroxymethyl) methyl-2-aminoethane sulfonic acid] at 10mM concentration. The inoculum, an actively growing culture, was filtered through a 0.5 μm polycarbonate “nuclepore” filter to prevent transfer of all but the smallest aggregates. Growth was assessed at specific periods by colony counts and 800 ml samples of organisms were fixed in situ with 2.5% glutaraldehyde for 3 hrs. at 4°C. Washed cells for sectioning were post-fixed in 0.8% OSO4 in veronal-acetate buffer pH 6.1 for 1 hr. at 21°C. HeLa cells were infected with a filtered inoculum of M. pneumoniae and incubated for 9 days in Leighton tubes with coverslips. The cells were then removed and processed for electron microscopy.

Review of the Radiation Damage Problem of Organic Specimens in Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 476-477
Author(s):  
L. Reimer
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Irradiation Time ◽  
Dose Effect ◽  
Primary Process ◽  
Thin Specimen ◽  
Secondary Damage ◽  
Small Doses ◽  
Micro Organisms ◽  
Damage Processes

Most information about a specimen is obtained by elastic scattering of electrons, but one cannot avoid inelastic scattering and therefore radiation damage by ionisation as a primary process of damage. This damage is a dose effect, being proportional to the product of lectron current density j and the irradiation time t in Coul.cm−2 as long as there is a negligible heating of the specimen.Therefore one has to determine the dose needed to produce secondary damage processes, which can be measured quantitatively by a chemical or physical effect in the thin specimen. The survival of micro-organisms or the decrease of photoconductivity and cathodoluminescence are such effects needing very small doses (see table).

Laboratory and in-situ analysis of comet dust

1988 ◽  
Vol 46 ◽  
pp. 8-9
Author(s):  
D.E. Brownlee ◽  
A.L. Albee
Keyword(s):  
Electron Microscopy ◽  
Solar System ◽  
Laboratory Study ◽  
Isotopic Analysis ◽  
Building Blocks ◽  
Sem Analysis ◽  
Early Solar System ◽  
Cometary Material ◽  
Comet Dust

Comets are primitive, kilometer-sized bodies that formed in the outer regions of the solar system. Composed of ice and dust, comets are generally believed to be relic building blocks of the outer solar system that have been preserved at cryogenic temperatures since the formation of the Sun and planets. The analysis of cometary material is particularly important because the properties of cometary material provide direct information on the processes and environments that formed and influenced solid matter both in the early solar system and in the interstellar environments that preceded it.The first direct analyses of proven comet dust were made during the Soviet and European spacecraft encounters with Comet Halley in 1986. These missions carried time-of-flight mass spectrometers that measured mass spectra of individual micron and smaller particles. The Halley measurements were semi-quantitative but they showed that comet dust is a complex fine-grained mixture of silicates and organic material. A full understanding of comet dust will require detailed morphological, mineralogical, elemental and isotopic analysis at the finest possible scale. Electron microscopy and related microbeam techniques will play key roles in the analysis. The present and future of electron microscopy of comet samples involves laboratory study of micrometeorites collected in the stratosphere, in-situ SEM analysis of particles collected at a comet and laboratory study of samples collected from a comet and returned to the Earth for detailed study.

Application of analytical electron microscopy to the study of partitioning of silicon in a 2 wt% Si eutectoid steel

1978 ◽  
Vol 36 (1) ◽  
pp. 616-617
Author(s):  
N. Ridley ◽  
S.A. Al-Salman ◽  
G.W. Lorimer
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Analytical Electron Microscopy ◽  
Eutectoid Steel ◽  
Minimum Diameter ◽  
Thin Foils ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Transformation Front

The application of the technique of analytical electron microscopy to the study of partitioning of Mn (1) and Cr (2) during the austenite-pearlite transformation in eutectoid steels has been described in previous papers. In both of these investigations, ‘in-situ’ analyses of individual cementite and ferrite plates in thin foils showed that the alloying elements partitioned preferentially to cementite at the transformation front at higher reaction temperatures. At lower temperatures partitioning did not occur and it was possible to identify a ‘no-partition’ temperature for each of the steels examined.In the present work partitioning during the pearlite transformation has been studied in a eutectoid steel containing 1.95 wt% Si. Measurements of pearlite interlamellar spacings showed, however, that except at the highest reaction temperatures the spacing would be too small to make the in-situ analysis of individual cementite plates possible, without interference from adjacent ferrite lamellae. The minimum diameter of the analysis probe on the instrument used, an EMMA-4 analytical electron microscope, was approximately 100 nm.

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