scholarly journals All That Glitters is not Gold: Approaches to Labeling for EM

2002 ◽  
Vol 10 (3) ◽  
pp. 24-26
Author(s):  
R.M. Albrecht ◽  
D.A. Meyer
Keyword(s):  
Heavy Metals ◽  
Spatial Resolution ◽  
Imaging Systems ◽  
Electron Microscopic ◽  
Microscopic Imaging ◽  
Virus Particles ◽  
Transmission Electron ◽  
Scanning Electron Microscopic ◽  
Electron Imaging ◽  
Scanning Electron

A large number of natural and synthetic species ranging from virus particles to small polymer beads have been employed over trie years as labels in electron microscopic applications. Perhaps the most useful and versatile of these labels are the colloidal heavy metals. The colloidal labels can be synthesized as round regular spheres in sizes from 1 to 150 nanometers in diameter and thus can be used where molecular and sub-molecular ranges of spatial resolution are required. They are electron “dense” and good emitters of secondary and back-scattered electrons and hence are readily detectable in both scanning electron microscopic imaging systems and transmission electron imaging systems. Larger particles, 10nm and above, can be identified via their shape in force based imaging systems.

A Comparative Study of Fractographic Replicas

1974 ◽  
Vol 32 ◽  
pp. 566-567
Author(s):  
Loren Anderson ◽  
Pat Pizzo ◽  
Glen Haydon
Keyword(s):  
Electron Microscopy ◽  
Electron Microscopic Examination ◽  
Direct Examination ◽  
Electron Microscopic ◽  
Reliable Technique ◽  
Service Failures ◽  
Transmission Electron ◽  
Mode Of Failure ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Transmission electron microscopy of replicas has long been used to study the fracture surfaces of components which fail in service. Recently, the scanning electron microscope (SEM) has gained popularity because it allows direct examination of the fracture surface. However, the somewhat lower resolution of the SEM coupled with a restriction on the sample size has served to limit the use of this instrument in investigating in-service failures. It is the intent of this paper to show that scanning electron microscopic examination of conventional negative replicas can be a convenient and reliable technique for determining mode of failure.

scholarly journals The Ascus Apex in Lichenized Fungi III. The Pertusaria-Type

1982 ◽  
Vol 14 (3) ◽  
pp. 205-217 ◽  
Author(s):  
Rosmarie Honegger
Keyword(s):  
Fine Structure ◽  
Side Branch ◽  
Functional Type ◽  
Electron Microscopic ◽  
Considerable Heterogeneity ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Elongation Process ◽  
Scanning Electron

AbstractOn the basis of light microscopic (LM), scanning electron microscopic (SEM) and transmission electron microscopic (TEM) investigations the Pertusaria-type of ascus is described as a particular functional type. The functionally unitunicate Pertusaria-type is characterized by its structure, staining properties, and by its particular mode of dehiscence. Tripartite ascus walls were observed in LM and TEM. The non-amyloid ascus wall is surrounded by a thin, amyloid outer layer. Both become amorphous at maturity and partly disintegrate. An apically thickened, amyloid inner layer reaches the base of the ascus. In its fine structure this amyloid inner layer resembles the material of the amyloid dome of Lecanora-type asci. It plays an important role during dehiscence and spore discharge. An elongation process was observed prior to dehiscence, at the end of which the ascus tip is situated above the hymenial surface. Dehiscence occurs by bursting or splitting of the whole ascus tip. The Pertusaria-type might represent a side-branch of evolution from bitunicate to unitunicate forms within the Lecanorales.Pertusaria-type asci are restricted to a small number of genera within the Pertusariaceae. A considerable heterogeneity in ascus structure and staining properties was observed within the Pertusariineae sensu Henssen & Jahns (1973) and Henssen (1976).

scholarly journals Scanning Electron Microscopic Study of Modified Chloroplasts in Senescing Broccoli Florets

HortScience ◽  
2000 ◽  
Vol 35 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Hirofumi Terai ◽  
Alley E. Watada ◽  
Charles A. Murphy ◽  
William P. Wergin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Structural Changes ◽  
Freeze Fracture ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Structural changes in chloroplasts of broccoli (Brassica oleracea L., Italica group) florets during senescence were examined using light microscopy, scanning electron microscopy (SEM) with freeze-fracture technique, and transmission electron microscopy (TEM) to better understand the process of chloroplast degradation, particularly at the advanced stage of senescence. Light microscopy revealed that chloroplasts, which initially were intact and green, became obscure in shape, and their color faded during senescence. Small, colored particles appeared in cells as the florets approached the final stage of senescence and became full- to dark-yellow in color. Scanning electron microscopy showed that stroma thylakoids in the chloroplast initially were parallel to each other and grana thylakoids were tightly stacked. As senescence advanced, the grana thylakoids degenerated and formed globules. The globules became larger by aggregation as senescence progressed, and the large globules, called “thylakoid plexus,” formed numerous vesicles. The vesicles ultimately were expelled into the cytosol, and the light microscope revealed many colored particles in the senescent cells. These results indicate that the degradation of chloroplasts in broccoli florets progresses systematically, with the final product being colored particles, which are visible in yellow broccoli sepal cells.

A scanning electron microscopic method for assessing surface topography of bladders

1984 ◽  
Vol 42 ◽  
pp. 40-41
Author(s):  
Betty I. Tarnowski ◽  
Gregory R. Schonbaum
Keyword(s):  
Electron Microscopy ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Step Procedure ◽  
Critical Point Drying ◽  
Scanning Electron Microscopic ◽  
Sampling Procedures ◽  
Electron Microscopic Method ◽  
Scanning Electron ◽  
Sem Analyses

Neither light microscopy nor transmission electron microscopy lend themselves to an accurate assessment of focal changes of epithelium: both techniques are limited by sampling procedures. The same limitation, however, does not apply to scanning electron microscopy (SEM) (1,2) which permits statistically meaningful analyses on a larger number of samples. The usefulness of such an approach was explored in our studies on the induction of damage to rat urothelium by cyclophosphamide (3,4) and its prevention by adjunct therapy with 2,3-dimercaptopropane sulfonate (DMPS). Portions of the bladder were sampled from the dome, central region and trigone and the tissue was prepared for SEM by dehydration in acetone, followed by critical point drying and gold coating. SEM analyses were performed in a two-step procedure using a Novascan scanning electron microscope at low (20X) and high (100X) magnifications.

scholarly journals Improved Biological Tissue Preparation Procedure for Scanning Electron Microscopic Imaging

2018 ◽  
Vol 24 (S1) ◽  
pp. 1308-1309
Author(s):  
Habeeb Alsudani ◽  
Soumitra Ghoshroy ◽  
Joseph Quattro ◽  
Matthew Greenwold ◽  
Roger Sawyer
Keyword(s):  
Biological Tissue ◽  
Preparation Procedure ◽  
Tissue Preparation ◽  
Electron Microscopic ◽  
Microscopic Imaging ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Scanning electron microscopic imaging of surface effects in desorption and nano-desorption electrospray ionization

2011 ◽  
Vol 46 (3) ◽  
pp. 256-261 ◽  
Author(s):  
Filip Kaftan ◽  
Olga Kofroňová ◽  
Oldřich Benada ◽  
Karel Lemr ◽  
Vladimír Havlíček ◽  
...  
Keyword(s):  
Electrospray Ionization ◽  
Desorption Electrospray Ionization ◽  
Surface Effects ◽  
Electron Microscopic ◽  
Microscopic Imaging ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

3. Scanning Electron Microscopic Appearance of Rat Otocyst of the Twelfth Postcoital Day Elaboration of a Method

1977 ◽  
Vol 86 (1_suppl) ◽  
pp. 29-36 ◽  
Author(s):  
William F. Marovitz ◽  
Khalid M. Khan
Keyword(s):  
Critical Point ◽  
Pressure Head ◽  
Electron Microscopic ◽  
Microscopic Appearance ◽  
Initial Fixation ◽  
Transmission Electron ◽  
Critical Point Drying ◽  
Scanning Electron Microscopic ◽  
Electron Microscopic Appearance ◽  
Scanning Electron

A method for removal, fixation, microdissection, and drying of early rat otocyst for examination by the scanning electron microscope is elaborated. Tissues were dissected, fixed as for conventional transmission electron microscopy and dried by critical point evaporation using amylacetate as the transitional fluid and carbon dioxide as the pressure head. Otocysts were either dissected at the time of initial fixation, or subsequent to drying. The otocyst of the 12th postcoital day was used as a model system in this preliminary report. Critical point drying retained the overall configuration and the fine ultrastructural detail of the otocyst. The interior otocystic surface was visualized and cilia bearing cells of the luminal surface were identified. Most if not all of these cells had a conspicuous, but short kinocilium which terminated in an ovoid bulb. The scanning electron microscopic appearance was correlated to the transmission electron microscopic image seen in the second paper in this Supplement.

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