scholarly journals An Effective Method of Preparing Sections of Bacillus polymyxa Sporangia and Spores for Electron Microscopy

1960 ◽  
Vol 7 (2) ◽  
pp. 373-376 ◽  
Author(s):  
Pauline E. Holbert
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Electron Micrographs ◽  
Epoxy Resins ◽  
Bacillus Polymyxa ◽  
Thin Sections ◽  
Similar Images ◽  
Embedding Medium ◽  
First Time ◽  
Diamond Knife

Bacillus polymyxa sporangia and spores were prepared for examination in the electron microscope by methods whose critical features were apparently: judicious use of vacuum, to encourage complete penetration of the embedding medium; the use of epoxy resins as embedding media; and cutting of the thin sections with a diamond knife. Electron micrographs of material prepared in this manner exhibit undeformed sporangial sections. Some of the structures revealed have been shown before, though perhaps less distinctly; other structures are revealed here for the first time. While this single study does not pretend to elucidate all the complexities of sporulation in bacteria, these and similar images should make this possible, and some mention of the preparatory techniques that lead to them seems advisable at this time.

Frozen Sectioning of Porous Polymer Membranes for Electron Microscopy

1968 ◽  
Vol 26 ◽  
pp. 412-413
Author(s):  
E. F. Koch
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Room Temperature ◽  
Polymer Membranes ◽  
Polymer Membrane ◽  
Porous Polymer ◽  
Thin Sections ◽  
The One ◽  
Diamond Knife

A technique has been devised using a diamond knife ultramicrotome in conjunction with a freezing head to prepare thin sections of porous polymer membranes. The thin sections are examined and photographed in transmission with an electron microscope to reveal the hole sizes in the membranes.Attempts to microtome a particular type of porous polymer membrane at room temperature proved unsuccessful, since the polymer membrane was not strong enough to support Itself when cut to appropriate viewing thicknesses of about 250 Å to 500 Å. It was thought that some degree of rigidity could be imparted to the polymer by cooling it below room temperature. Therefore, a freezing head was made for the Porter-Blum microtome, similar to the one developed by Crudgington, Fig. 1.

Albumins as Embedding Media for Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 422-423 ◽  
Author(s):  
J. L. Farrant ◽  
J. D. McLean
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Temperature ◽  
Biological Material ◽  
Globular Proteins ◽  
The Past ◽  
Antibody Staining ◽  
Thin Sectioning ◽  
Embedding Medium

For electron microscope techniques such as ferritin-labeled antibody staining it would be advantageous to have available a simple means of thin sectioning biological material without subjecting it to lipid solvents, impregnation with plastic monomers and their subsequent polymerization. With this aim in view we have re-examined the use of protein as an embedding medium. Gelatin which has been used in the past is not very satisfactory both because of its fibrous nature and the high temperature necessary to keep its solutions fluid. We have found that globular proteins such as the serum and egg albumins can be cross-linked so as to yield blocks which are suitable for ultrathin sectioning.

SEM Examination of a Used Diamond Knife

1971 ◽  
Vol 29 ◽  
pp. 452-453
Author(s):  
J. Temple Black
Keyword(s):  
Electron Microscope ◽  
High Voltage ◽  
High Magnification ◽  
Metallic Materials ◽  
Wide Spread ◽  
Thin Sections ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron ◽  
Diamond Knife

Since its introduction by Fernandez-Moran, the diamond knife has gained wide spread usage as a common material for cutting of thin sections of biological and metallic materials into thin films for examination in the transmission electron microscope. With the development of high voltage E.M. and scanning transmission E.M., microtomy applications will become increasingly important in the preparation of specimens. For those who can afford it, the diamond knife will thus continue to be an important tool to accomplish this effort until a cheaper but equally strong and sharp tool is found to replace the diamond, glass not withstanding.In Figs. 1 thru 3, a first attempt was made to examine the edge of a used (β=45°) diamond knife by means of the scanning electron microscope. Because diamond is conductive, first examination was tried without any coating of the diamond. However, the contamination at the edge caused severe charging during imaging. Next, a thin layer of carbon was deposited but charging was still extensive at high magnification - high voltage settings. Finally, the knife was given a light coating of gold-palladium which eliminated the charging and allowed high magnification micrographs to be made with reasonable resolution.

Ultrastructure of Testicular Spermatozoon of the Fish Oreochromis Niloticus

1988 ◽  
Vol 46 ◽  
pp. 278-279
Author(s):  
T. Guha ◽  
A. Q. Siddiqui ◽  
P. F. Prentis
Keyword(s):  
Electron Microscope ◽  
Oreochromis Niloticus ◽  
Osmium Tetroxide ◽  
Sperm Cells ◽  
Adult Fish ◽  
Testicular Sperm ◽  
Thin Sections ◽  
Important Fish ◽  
Testicular Spermatozoon ◽  
Diamond Knife

Tilapia, Oreochromis niloticus, is an economically important fish in Saudi Arabia. Elucidation of reproductive biology of this species is necessary for successful breeding program. In this paper we describe fine structure of testicular sperm cells in O, niloticus.Testes from young adult fish were fixed in gluteraldehyde (2%) and osmium tetroxide (1%), both in cacodyl ate buffer. Specimens were processed in the conventional way for electron microscopy and thin sections of tissues (obtained by cutting the blocks with a diamond knife) were stained by ura- nyl acetate and lead citrate. These were examined in a Carl Zeiss electron microscope operated at 40 kV to 60 kV. Sperm cells were obtained from testes by squeezing them in cacodyl ate buffer. They were fixed in gluteraldehyde (2%) in the same buffer, air dried, gold coated and then examined in a Philips scanning electron microscope (SEM) operated at 25kV.The spermatozoon of O. niloticus is consisting of head, midpiece and tail (Fig. 1).

SCANNING ELECTRON MICROSCOPE: POSSIBILITIES FOR STUDYING KIDNEY DISEASES

2020 ◽  
pp. 176-182
Author(s):  
Mamaeva S.N. ◽  
Vinokurov R.R. ◽  
Munkhalova Ya.A. ◽  
Dyakonova D.P. ◽  
Platonova V.A. ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Filtration Rate ◽  
Kidney Diseases ◽  
First Time ◽  
Scanning Electron

Currently, due to the intensive development of high-tech science-intensive medical and research devices, more and more attention is paid to the development of diagnostics of rare and difficult to diagnose diseases. It is known that among numerous nephropathies, hematuria may be the only symptom of kidney and urinary tract diseases, which complicates their diagnosis and treatment. In order to develop new approaches for the diagnosis of nephropathies, the authors have been studying the morphology of red blood cells in the blood and urine of children and adults using a scanning electron microscope for several years. The paper presents the results of studies of children with various kidney diseases, including IgA-nephropathy, and chronic glomerulonephritis. Scanning electron microscopy was used for the first time to detect nanoparticles on the surface of red blood cells, the size of which is comparable to the size of viruses, which became the basis for one of the authors ' assumptions, namely, the possible transport of certain types of viruses by red blood cells. Thus, some kidney diseases could be considered virus-associated. This paper presents for the first time the results of determining the glomerular filtration rate of both kidneys separately in the study of separate kidney function and of the study of urine smears obtained during catheterization of the ureters in patients with hydronephrosis of one of the kidneys by scanning electron microscopy. As in previous studies, nanoparticles were found on the surface of red blood cells, which leads to the conclusion about the possible viral nature of the disease of the considered patient. In addition, smear images obtained using a microscope showed a significant difference in the elements of the right and left kidneys urine, which did not contradict the data on the study of glomerular filtration rate. According to the authors, the capabilities of the scanning electron microscope can be applied in fundamental research of kidney diseases at the cellular and molecular levels, forming new ideas about their origin, as well as on the basis of which new methods of non-invasive diagnostics can be built.

scholarly journals Capture and scanning electron microscopy of individual snow crystals

1994 ◽  
Vol 40 (134) ◽  
pp. 195-197
Author(s):  
E. W. Wolff ◽  
A. P. Reid
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Liquid Nitrogen Temperature ◽  
Experimental Methods ◽  
Snow Crystal ◽  
Snow Crystals ◽  
First Time ◽  
Scanning Electron

AbstractA snow crystal has been successfully collected on to a scanning electron microscope (SEM) stub in central Greenland. It was preserved at liquid-nitrogen temperature for 5 months, prior to examination in the SEM. This is believed to be the first time a snow crystal has been observed directly in the SEM and offers some new experimental methods for understanding crystals and their chemistry.

Cytoplasmic surface and intramembrane components of rat heart gap junctional proteins

1984 ◽  
Vol 246 (6) ◽  
pp. H865-H875 ◽  
Author(s):  
C. K. Manjunath ◽  
G. E. Goings ◽  
E. Page
Keyword(s):  
Electron Microscopy ◽  
Gap Junctions ◽  
Electron Micrographs ◽  
Rat Heart ◽  
Major Protein ◽  
Thin Sections ◽  
Cytoplasmic Surface ◽  
Sds Page ◽  
Junction Protein ◽  
Major Protein Band

Gap junctions were purified from rat hearts in the presence of absence of proteolysis inhibitors and examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and electron microscopy of thin sections. In absence of proteolysis inhibitors or in presence of ethylenediaminetetraacetic acid or leupeptin, gap junctions contained a single major protein band at relative molecular weight (Mr) 29,500 and minor bands at Mr 44,000–47,000, 17,750, and 16,500 and showed smooth cytoplasmic surfaces in electron micrographs. SDS-PAGE of junctions prepared with phenylmethylsulfonylfluoride (PMSF) showed markedly decreased intensity of the Mr 29,500 band and increased intensity of bands at Mr 44,000, 45,500, and 47,000; electron microscopy of these gap junctions showed presence of a fuzzy layer on their cytoplasmic surfaces. Urea (8 M) could not remove this fuzzy layer. In electron micrographs of rat ventricular myocytes, cytoplasmic surfaces of gap junctions were fuzzy. We conclude that rat heart gap junction protein consists of an intramembrane component (Mr 29,500) that extends into the “gap” and a cytoplasmic surface component (Mr 14,500–17,500) that corresponds to the fuzzy layer and is hydrolyzable by a serine protease.

scholarly journals OBSERVATIONS ON THE FINE STRUCTURE OF THE MACRONUCLEUS OF TOKOPHRYA INFUSIONUM

1955 ◽  
Vol 1 (5) ◽  
pp. 421-428 ◽  
Author(s):  
Maria A. Rudzinska ◽  
Keith R. Porter
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Cross Sections ◽  
Regular Structure ◽  
Metaphase Chromosomes ◽  
Thin Sections ◽  
Significant Aspect ◽  
Parallel Lines ◽  
Chromatin Material ◽  
First Time

The macronucleus in Tokophrya infusionum is composed of numerous Feulgen-positive chromatin bodies (about 0.5 µ in diameter) which appear in thin sections as a dense spongework, homogeneous throughout. The same appearance characterizes metaphase chromosomes of higher forms. Some chromatin bodies of the macronucleus were found to possess a highly organized structure in certain old organisms. This structure appears in cross-sections as a honeycomb and in longitudinal sections as parallel lines about 120 A in diameter evenly spaced (about 230 A). As far as is known this is the first time a regular structure has been found in bodies of chromosomal character at the dimensional level presently explored by electron microscopy. The demonstration that OsO4 can preserve order in chromatin material is another significant aspect of these findings.

Scanning electron microscopy of the cuticular armature of the nematode Gnathostoma spinigerum Owen, 1836 from cats in Laos

1990 ◽  
Vol 64 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Tomáš Scholz ◽  
Oleg Ditrich
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Spatial Arrangement ◽  
Felis Catus ◽  
The Body ◽  
Immature Female ◽  
Gnathostoma Spinigerum ◽  
First Time ◽  
Scanning Electron

ABSTRACTThe body surface of an immature female Gnathostoma spinigerum found for the first time in the definitive host (Felis catus f. domestica) in Laos was studied using a scanning electron microscope. All types of cuticular spines, which are one of the most important features for species identification of gnathostomid nematodes, together with their spatial arrangement, are described and figured.

Nucleation in silver azide: an investigation by electron microscopy and diffraction

1955 ◽  
Vol 229 (1176) ◽  
pp. 135-142 ◽  
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Single Crystals ◽  
Electron Micrographs ◽  
The Other ◽  
Metallic Silver ◽  
Silver Azide ◽  
Cubic Lattice ◽  
Early Stages ◽  
Last Stage

The beam of an electron microscope has been used to decompose single crystals of silver azide into nitrogen and metallic silver. The decomposition was slow enough to allow electrondiffraction photographs and electron micrographs to be taken at various stages of the decomposition. From these observations it is possible to follow very closely the process of nucleation. The diffraction photographs show that two forms of silver result, one highly oriented and the other randomly oriented. The microscope identifies the two forms. The randomly oriented silver appears to separate at the boundaries of a substructure of the crystal. The highly oriented silver exists as discrete nuclei, of dimensions of the order 0.1 x 0.1 x 0.05p, probably formed near the surface of the silver azide crystal. The nuclei consist of normal metallic silver only at the end of the decomposition. There is no evidence for the formation in the early stages of a small speck of metallic silver which then grows. Rather, a nucleus is a region into which silver diffuses to build up a face-centred cubic lattice of parameter greater than that of normal silver, and which uses the silver positions in the silver azide lattice as the basis for this build-up. In the last stage a collapse to normal metallic silver takes place. During decomposition the size of a nucleus does not appear to change, but the density increases.

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