What happens to the normal cytoplasmic features of fish erythrophores when, under identical conditions of culture, the erythrophores are fused with normal rat kidney cells?

1992 ◽  
Vol 50 (1) ◽  
pp. 546-547
Author(s):  
Keith R. Porter ◽  
Karen L. Anderson
Keyword(s):  
Electron Microscopy ◽  
Rat Kidney ◽  
Experimental Studies ◽  
Cell Types ◽  
Small Population ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
Carbon Coated ◽  
Normal Rat

We have shown that a small population of normal cells can be cultured from the scales of the squirrel fish, Holocentrus rufus. They can be grown directly on Formvar-carbon-coated gold grids and, while still on the grids they can be fixed, stained and dehydrated for high voltage electron microscopy. One of the cell types (epidermal) spreads out on the carbon-coated surface and is thin enough in most parts for conventional (100kV) electron microscopy. The aspect of wholeness represented in these qells should not be overlooked for it provides information that might be missed in a series of thin sections where the sample is obviously smaller. Furthermore, if experimental studies are contemplated, they can be made while the cells are still alive and available for light microscopy.

On the High Voltage Electron Microscopy (1 MeV) of Biological Thick Sections

1972 ◽  
Vol 30 ◽  
pp. 464-465
Author(s):  
William H. Massover
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Present Report ◽  
Biological Tissues ◽  
Specimen Preparation ◽  
Technical Problems ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron

Stereoscopic examination of thick sections of fixed and embedded biological tissues by high voltage electron microscopy has been shown to allow direct visualization of three-dimensional fine structure. The present report will consider the occurrence of some new technical problems in specimen preparation and Image interpretation that are not common during lower voltage studies of thin sections.Thick Sectioning and Tissue Coloration - Epon sections of 0.5 μm or more that are cut with glass knives do not have a uniform thickness as Judged by their interference colors; these colors change with time during their flotation on the knife bath, and again when drying onto the specimen support. Quoted thicknesses thus must be considered only as rough estimates unless measured in specific regions by other methods. Chloroform vapors do not always result in good spreading of thick sections; however, they will spread spontaneously to large degrees after resting on the flotation bath for several minutes. Ribbons of thick sections have been almost impossible to obtain.

Video Graphics and High-Voltage Electron Microscopy For Analysis of Microtubule Distributions In Fixed Cells

1990 ◽  
Vol 48 (1) ◽  
pp. 524-525
Author(s):  
Richard Mcintosh ◽  
David Mastronarde ◽  
Kent McDonald ◽  
Rubai Ding
Keyword(s):  
Electron Microscopy ◽  
Cross Sections ◽  
Cell Shape ◽  
Video Camera ◽  
Computer Memory ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
Morphogenetic Event ◽  
Set Of Points

Microtubules (MTs) are cytoplasmic polymers whose dynamics have an influence on cell shape and motility. MTs influence cell behavior both through their growth and disassembly and through the binding of enzymes to their surfaces. In either case, the positions of the MTs change over time as cells grow and develop. We are working on methods to determine where MTs are at different times during either the cell cycle or a morphogenetic event, using thin and thick sections for electron microscopy and computer graphics to model MT distributions.One approach is to track MTs through serial thin sections cut transverse to the MT axis. This work uses a video camera to digitize electron micrographs of cross sections through a MT system and create image files in computer memory. These are aligned and corrected for relative distortions by using the positions of 8 - 10 MTs on adjacent sections to define a general linear transformation that will align and warp adjacent images to an optimum fit. Two hundred MT images are then used to calculate an “average MT”, and this is cross-correlated with each micrograph in the serial set to locate points likely to correspond to MT centers. This set of points is refined through a discriminate analysis that explores each cross correlogram in the neighborhood of every point with a high correlation score.

scholarly journals The chondriome of selected trypanosomatids. A three-dimensional study based on serial thick sections and high voltage electron microscopy.

1975 ◽  
Vol 66 (2) ◽  
pp. 404-413 ◽  
Author(s):  
J J Paulin
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Three Dimensional ◽  
Flagellar Pocket ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
Trypomastigote Form ◽  
High Voltage Electron ◽  
Three Dimensional Models

The unitary nature of the chondriome of two species of trypanosomatids, Blastocrithidia culicis and Trypanosoma cruzi, has been demonstrated by utilizing serial thick-sectioning techniques combined with high voltage electron microscopy. Profiles of mitochondrial elements seen in thin sections and suspected to be parts of a continuum were confirmed by serial thick sectioning (0.25-0.50 mum thick) and stereopair analysis to be parts of the same mitochondrion. Three-dimensional models obtained from tracings of mitochondrial profiles on cellulose acetate reveal the mitochondrion of B. culicis to consist of a posterior mass with six tubular extensions extending upward and terminating in the anterior apex. The kinetoplast was found suspended between two of the tubular extensions, or less frequently, protuding as a nodule from one of the extensions. A bifurcation of one of the extensions was found in some specimens. The mitochondrion of T. cruzi consists of a triangular-shaped convoluted tubule, the base being the kinetoplast portion while the apex is directed posteriorly. The mitochondrion bifurcates behind the flagellar pocket, lateral to the kinetoplast, sending two entwined extensions into the tenuous anterior apex. Whether the mitochondrion of T. cruzi is unitary in the trypomastigote form was not determined in this study, since only epimastigote forms were used.

Observations on Developing Blood Vessels in Rat Spinal Cord—A High Voltage Electron Microscopy Study

1974 ◽  
Vol 32 ◽  
pp. 66-67
Author(s):  
Richard S. Hannah
Keyword(s):  
Electron Microscopy ◽  
Spinal Cord ◽  
High Voltage ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Transmission Electron

The formation of junctional complexes between endothelial cell processes was examined in rat spinal cords, from age birth to six weeks. Segments of spinal cord were removed from the region of the cervical enlargement and fixed. For comparative purposes, animals from each time group were subdivided into groups, fixed by either immersion or perfusion with an aldehyde combination in sodium cacodylate buffer and embedded in Araldite. Thin sections were examined by conventional transmission electron microscopy. Thick sections (0.5μ - 1.0μ) were stained with uranyl magnesium acetate for four hours at 60°C and lead citrate for 30 mins. and examined in the AEI Mark II High Voltage Electron Microscope.

High Voltage Electron Microscopy of Muscle

1969 ◽  
Vol 27 ◽  
pp. 96-97
Author(s):  
Robert V. Rice ◽  
J. S. Lally
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
High Voltage ◽  
Striated Muscle ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Cell Biol ◽  
Adjacent Structures

Several structures have been proposed to account for the appearance of Z and M-lines seen in thin sections of striated muscle. The high penetrating power of 800,000 to 1,000,000 volt electrons coupled with stereology offers a unique opportunity to resolve the complicated fine structure of Z and M-lines. In addition use has been made of the recently developed extraction and reconstitution of Z and M-lines (Stromer, Hartshorne, Mueller, and Rice, J. Cell Biol., 40, 167, 1969). Removal of portions of these structures helps to eliminate confusion due to adjacent structures.

Histo-grade diamond knives may be an appropriate tool for high-voltage electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 296-297
Author(s):  
M.E. Rock ◽  
J.A. Anderson ◽  
P.S. Binder
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Stereo Pair ◽  
Specimen Thickness ◽  
Serial Sections ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Diamond Knife

High voltage electron microscopy (HVEM) has been employed in various ways (whole mounts of cells stereo pair imaging, axial tomography, and serial sections for reconstruction) to elucidate three dimensional (3-D) ultrastructural data. The increased specimen thickness allows further data analysis unobtainable from ultra-thin sections. HVEM can reduce the number of sections needed in 3-D reconstructiortby approximately ten times over conventional transmission electron microscopy (CTEM). But increasing section thickness also increases wear on the diamond knife used to section. We have compared the serial sections obtained from a histo-grade diamond knife with those from an E.M. grade ultra-knife. Both sets of sections were cut 0.5 μm thick from the same block, and evaluated under the one million volt beam of the HVEM.

The application of three-dimensional tomographic reconstruction methods to high-voltage electron microscopy

1987 ◽  
Vol 45 ◽  
pp. 570-573
Author(s):  
B. F. McEwen ◽  
C. L. Rieder ◽  
M. Radermacher ◽  
R. A. Grassucci ◽  
J. N. Turner ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Three Dimensional ◽  
Depth Of Field ◽  
Specimen Thickness ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Reconstruction Methods

High-voltage electron microscopy (HVEM) has considerably increased the thickness limit of biological specimens that can be visualized at high resolution. Because of its increased penetration power, HVEM is potentially the most powerful tool available for obtaining three-dimensional (3D) information concerning the structure of cells. In the past, such information was primarily obtained from serial thin sections or techniques based on surface shadowing, but these methods have severe problems and limitations which can only be overcome by imaging greater depths in the samples (see refs. 1 and 2). HVEM has yet to realize its potential for 3D structural determination because of the confusion arising from the overlap of features at different depths in the sample. Due to the relatively large depth of field, which exceeds the specimen thickness, HVEM (like all electron microscopy) produces an image that is essentially a projection of the sample.

High-voltage electron microscopy of adrenal medulla: continuities between organelles

1978 ◽  
Vol 36 (2) ◽  
pp. 20-21
Author(s):  
Stephen W. Carmichael ◽  
David J. Smith
Keyword(s):  
Electron Microscopy ◽  
Adrenal Medulla ◽  
High Voltage ◽  
Membrane System ◽  
Vascular Perfusion ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
University Of Colorado ◽  
High Voltage Electron ◽  
Carbon Coated

The adrenal medulla of the cat and rat has been studied during resting and stimulated conditions by high-voltage electron microscopy (HVEM). It was our objective to study the relationship of cytoplasmic organelles to each other and the cytoplasmic membrane system as they participate in the process of secretion.The adrenals were fixed by vascular perfusion with buffered aldehyde solutions. The perfusion was immediately preceeded by acetylcholine (1 mg/ml) in some cats. In other cats and rats the perfusion was preceeded by insulin (5 IU/kg; IV) at 0, 4, 24, 48, 72 and 96 hr. intervals. The tissue was post-fixed with OsO4, KMn04, K4Fe (CN)6, K2Cr207, ZnIOsO4, Pb and Cu citrate, U acetate, and 3-3' dilminobenzidine singly and in specific combinations. Blocks were dehydrated in acetone and embedded in Epon-Araldite. Ultrathin and thick (0.5 - 2 μm) sections were cut on diamond and glass knives and mounted on carbon-coated copper grids. Specimens were examined at 50-100 KV on conventional TEM and at 800-1000 KV at the HVEM facilities at U.S. Steel Research Laboratory, Monroeville, PA, and University of Colorado, Boulder, CO.

The Sarcoplasmic Reticulum of Frog Slow and Twitch Muscle Fibers as Revealed by Stereoscopic High Voltage Electron Microscopy

1975 ◽  
Vol 33 ◽  
pp. 552-553 ◽  
Author(s):  
Craig H. Bailey ◽  
Lee D. Peachey
Keyword(s):  
Electron Microscopy ◽  
Sarcoplasmic Reticulum ◽  
High Voltage ◽  
Muscle Fibers ◽  
Three Dimensional ◽  
Tissue Slices ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron

Our present understanding of the distribution and morphology of the sarcoplasmic reticulum (SR) in frog slow and twitch muscle fibers has been derived largely from the examination of thin sections by electron microscopy. This conventional approach to the study of an organelle as complex as the SR is limited to a degree by section thickness, and the extraction of three-dimensional information must usually be gathered from an extensive collection of two-dimensional images. The present study represents an alternative approach to the problem of investigating the three-dimensional organization of the SR by utilizing high voltage electron microscopy (HVEM) and examining stereoscopic images of selectively stained 1.0 /μm thick slices of muscle tissue.Slow and twitch fibers from the distal fiber bundles of the frog (Rana pipiens) cruralis muscle were processed for electron microscopy according to the selective SR staining technique (DAB-H2O2 and Os-ferrocyanide) developed by Waugh. Tissue slices from 0.25 to 1.0 μm in thickness were cut on a diamond knife, mounted on grids either with or without plastic support films, and examined using the JEM-1000 microscope at the University of Colorado operating at an accelerating voltage of 1000 kV.

HVEM tomography of the Golgi apparatus: A structural study of the trans-cisternae and trans-Golgi network

1994 ◽  
Vol 52 ◽  
pp. 196-197
Author(s):  
Mark S. Ladinsky ◽  
James R. Kremer ◽  
Paul S. Furcinitti ◽  
Kathryn E. Howell ◽  
J.Richard McIntosh
Keyword(s):  
Golgi Apparatus ◽  
Rat Kidney ◽  
Uranyl Acetate ◽  
Fiducial Markers ◽  
Axial Tomography ◽  
High Voltage Electron Microscopy ◽  
Trans Golgi Network ◽  
Voltage Electron ◽  
Normal Rat ◽  
Golgi Network

The Golgi apparatus is a membranous organelle that plays central roles in the secretory processes of eukaryotic cells. The apparatus consists of multiple convoluted cisternae, some of which are connected to a tubulo-vesicular system known as the trans-Golgi network (TGN). The TGN is thought to be the primary site for sorting and targeting of lipids and proteins to other cellular locations. Only a few studies have addressed the 3-D structure of the Golgi apparatus, and fewer still have focused on the structure of the TGN.We have employed high voltage electron microscopy (HVEM) and computer axial tomography to study the TGN in 3-D. For these experiments, the trans-most cisternae and TGN of normal rat kidney (NRK) cells were labeled by photoconversion of internalized BODIPY-ceramide. Cells were then postfixed and embedded in Epon-Araldite. Semithick (250nm) sections were cut, post-stained with uranyl acetate and lead citrate, and surface-labeled with 15nm colloidal gold to provide fiducial markers for image alignment. Sections were viewed at 18,300x in a JEM-1000 HVEM operating at 1MeV.

Sign in / Sign up

Export Citation Format

Share Document