scholarly journals LOCALIZATION OF STRUCTURAL POLYMERS IN THE CELL WALL OF NEUROSPORA CRASSA

1967 ◽  
Vol 35 (2) ◽  
pp. 295-302 ◽  
Author(s):  
P. R. Mahadevan ◽  
E. L. Tatum
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Electron Microscope ◽  
Neurospora Crassa ◽  
Outer Layer ◽  
Light Microscope ◽  
Structural Integrity ◽  
Selective Removal ◽  
Microscope Examination ◽  
Structural Polymers

The distribution and localization of structural polymers in the cell wall of Neurospora crassa has been studied by selective removal and light and electron microscope examination. Observations with the light microscope indicated that each polymer by itself can provide structural integrity to the cell wall. Examination by electron microscopy showed that the cell wall consists of an outer layer of thick fibrils, identified chemically as a glucan-peptide-galactosamine complex, and an inner layer made up of ß-1,3 glucan and thin fibrils of chitin.

In vitro development of isolated ectoderm from axolotl gastrulae

Development ◽  
1984 ◽  
Vol 80 (1) ◽  
pp. 321-330
Author(s):  
Jonathan M. W. Slack
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Outer Layer ◽  
Microscope Examination ◽  
Animal Pole ◽  
In Vitro Development ◽  
Electron Microscope Examination ◽  
Vitro Development

The development of ectoderm isolated from the animal pole of axolotl gastrulae is monitored by light microscopy, electron microscopy and analysis of newly synthesized proteins, glycoproteins and glycolipids. When control embryos are undergoing neurulation it is shown that the explants autonomously begin to express epidermal markers and do not express mesodermal markers. However the results suggest that not all the cells become epidermal and electron microscope examination shows that only the outer layer does so, the inner cells remaining undifferentiated.

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

scholarly journals ELECTRON MICROSCOPY OF THE NUCLEAR MEMBRANE OF AMOEBA PROTEUS

1956 ◽  
Vol 2 (4) ◽  
pp. 445-448 ◽  
Author(s):  
Marie H. Greider ◽  
Wencel J. Kostir ◽  
Walter J. Frajola
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Nuclear Membrane ◽  
Outer Layer ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Cell Types ◽  
Amoeba Proteus ◽  
Nuclear Membranes ◽  
Thin Sectioning

An electron microscope study of the nuclear membrane of Amoeba proteus by thin sectioning techniques has revealed an ultrastructure in the outer layer of the membrane that is homologous to the pores and annuli observed in the nuclear membranes of many other cell types studied by these techniques. An inner honeycombed layer apparently unique to Amoeba proteus is also described.

Electron microscopy of the replicative events of A25 bacteriophages in group A streptococci

1972 ◽  
Vol 18 (1) ◽  
pp. 93-96 ◽  
Author(s):  
S. E. Read ◽  
R. W. Reed
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Electron Microscope ◽  
Nucleic Acid ◽  
Group A Streptococcus ◽  
Group A Streptococci ◽  
Virulent Phage ◽  
Acid Pool ◽  
Group A ◽  
A Cell

The replicative events of a virulent phage (A25) infection of a group A Streptococcus (T253) were studied using the electron microscope. The first intracellular evidence of phage replication in a cell occurred 30 min after infection with arrest of cell division and increase in the nucleic acid pool. Phage heads were evident in the nucleic acid pool of the cells 45 min after infection. Release of phages occurred by splitting of the cell wall along discrete lines. This appeared to be at sites of active wall synthesis, i.e., near the region of septum formation. Many phage components were released but relatively few complete phages indicating a relatively inefficient replicative system.

scholarly journals AN ELECTRON MICROSCOPE STUDY OF THE EMBRYOLOGY OF THE INTERCALATED DISC IN THE HEART OF THE RABBIT

1957 ◽  
Vol 3 (2) ◽  
pp. 193-202 ◽  
Author(s):  
Alan R. Muir
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Cardiac Muscle ◽  
Microscope Study ◽  
Light Microscope ◽  
Electron Microscope Study ◽  
Muscle Cells ◽  
Intercalated Disc ◽  
Adult Cell ◽  
Embryonic Muscle

Prenatal and postnatal cardiac muscle from rabbits has been studied by electron microscopy, after osmium fixation and methacrylate embedding. The observations showed that 1. Cell membranes divide the muscle into cellular units from the youngest embryo which was studied (9½ days after coitus) until the adult state. 2. The embryonic muscle cells contain only one nucleus, whereas the adult cell may be multinucleated. 3. At all stages of development, wherever a myofibrillar axis crosses a cellular boundary, the myofilaments are interrupted by an intercalated disc. 4. With age, increase in size and complexity of the discs render them recognisable by the light microscope.

scholarly journals Individual microtubules viewed by immunofluorescence and electron microscopy in the same PtK2 cell

1978 ◽  
Vol 77 (3) ◽  
pp. R27 ◽  
Author(s):  
M Osborn ◽  
RE Webster ◽  
K Weber
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscope ◽  
Immunofluorescence Microscopy ◽  
Uranyl Acetate ◽  
Tubulin Antibodies ◽  
Ptk2 Cell ◽  
Cytoplasmic Microtubules ◽  
Triton X ◽  
Microtubular Structures

PtK2 cells were grown on gold grids and treated with Triton X-100 in a microtubule stabilizing buffer. The resulting cytoskeletons were fixed with glutaraldehyde and subjected to the indirect immunofluorescence procedure using monospecific tubulin antibodies. Grids were examined first by fluorescence microscopy, and the display of fluorescent cytoplasmic microtubules was recorded. The grids were then stained with uranyl acetate and the display of fibrous structures recorded by electron microscopy. Thus the display of cytoplasmic microtubular structures in the light microscope and the electron microscope can be compared within the same cytoskeleton. The results show a direct correspondence of the fluorescent fibers in the light microscope with uninterrupted fibers of diameter approximately 550 A in the electron microscope. This is the diameter reported for a single microtubule decorated around its circumference by two layers of antibody molecules. Thus under optimal conditions immunofluorescence microscopy can visualize individual microtubules.

scholarly journals Scanning Electron Microscopy Observations of Loa loa (Nematoda)

2020 ◽  
Vol 11 (2) ◽  
pp. 486-492
Author(s):  
Jens Anibal Juul ◽  
Vegard Asgeir Forsaa ◽  
Tor Paaske Utheim ◽  
Endre Willassen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Case Report ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Loa Loa ◽  
Scanning Electron

We present a case report of periocular Loa loa. The key feature of L. loa distinguishing it from other human filarial parasites are cuticular bosses, which are presented in images from a light microscope and a scanning electron microscope. The cuticular bosses could be divided into three subtypes not previously described.

Bridging the Resolution Gap: Correlated 3D Light and Electron Microscopic Analysis of Large Biological Structures

1999 ◽  
Vol 5 (S2) ◽  
pp. 526-527
Author(s):  
Maryann E. Martone
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Surface Area ◽  
Light Microscope ◽  
Microscopic Analysis ◽  
Electron Microscopic Analysis ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Biological Structures ◽  
Ganglion Neurons

One class of biological structures that has always presented special difficulties to scientists interested in quantitative analysis is comprised of extended structures that possess fine structural features. Examples of these structures include neuronal spiny dendrites and organelles such as the Golgi apparatus and endoplasmic reticulum. Such structures may extend 10's or even 100's of microns, a size range best visualized with the light microscope, yet possess fine structural detail on the order of nanometers that require the electron microscope to resolve. Quantitative information, such as surface area, volume and the micro-distribution of cellular constituents, is often required for the development of accurate structural models of cells and organelle systems and for assessing and characterizing changes due to experimental manipulation. Performing estimates of such quantities from light microscopic data can result in gross inaccuracies because the contribution to total morphometries of delicate features such as membrane undulations and excrescences can be quite significant. For example, in a recent study by Shoop et al, electron microscopic analysis of cultured chick ciliary ganglion neurons showed that spiny projections from the plasmalemma that were not well resolved in the light microscope effectively doubled the surface area of these neurons.While the resolution provided by the electron microscope has yet to be matched or replaced by light microscopic methods, one drawback of electron microscopic analysis has always been the relatively small sample size and limited 3D information that can be obtained from samples prepared for conventional transmission electron microscopy. Reconstruction from serial electron micrographs has provided one way to circumvent this latter problem, but remains one of the most technically demanding skills in electron microscopy. Another approach to 3D electron microscopic imaging is high voltage electron microscopy (HVEM). The greater accelerating voltages of HVEM's allows for the use of much thicker specimens than conventional transmission electron microscopes.

Mucilaginous film production by plant cells immobilised in a polyurethane or nylon matrix

1985 ◽  
Vol 63 (12) ◽  
pp. 2357-2363 ◽  
Author(s):  
M. J. C. Rhodes ◽  
R. J. Robins ◽  
R. J. Turner ◽  
J. I. Smith
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Plant Cells ◽  
The Matrix ◽  
Nylon Fibre ◽  
Scanning Electron

The surface features of plant cells immobilised in a matrix of either reticulated polyurethane foam or nylon fibre have been examined with the scanning electron microscope. It has been found that both cells and matrix are enveloped in a thin film, the appearance of which is very dependent on the method by which material is prepared for scanning electron microscopy. The structure is severely damaged by fixation and dehydration. Only in specimens examined in the frozen hydrated state is a structure seen compatible with that observed with the light microscope. From the way the appearance of the film is affected by different methods of preparation for the scanning electron microscope, it is suggested that the film is a hydrated mucilage. The importance of this film for the retention of cells within the matrix is discussed.

scholarly journals ELECTRON MICROSCOPY OF THE AMMONIACAL SILVER REACTION FOR HISTONES IN THE ERYTHROPOIETIC CELLS OF THE CHICK

1970 ◽  
Vol 45 (2) ◽  
pp. 235-245 ◽  
Author(s):  
Edith K. MacRae ◽  
Gerald D. Meetz
Keyword(s):  
Electron Microscopy ◽  
Stem Cells ◽  
Bone Marrow ◽  
Electron Microscope ◽  
Light Microscope ◽  
Color Difference ◽  
Erythroid Cell ◽  
Erythroid Cells ◽  
Cell Series ◽  
Ammoniacal Silver

The product of the postformalin ammoniacal silver reaction, which has been claimed to distinguish lysine-rich from arginine-rich histones with the light microscope on the basis of a color difference, was examined in developing erythroid cells of chick bone marrow with the electron microscope. Stem cells and early erythroblasts exhibit no, or little, ammoniacal silver reaction product, while small basophilic erythroblasts, polychromatophilic erythrocytes, and reticulocytes exhibit an increasing amount of reaction product as maturation proceeds. The reaction product is in the form of discrete electron-opaque particles associated with heterochromatin. The ammoniacal silver reaction in the erythroid cell series is interpreted as reflecting either the accumulation of newly synthesized arginine-rich histones or changes in the availability of reactive sites in preformed histones.

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