The arrangement of myosin on the surface of paramyosin filaments in the white adductor muscle of Crassostrea angulata

1974 ◽  
Vol 186 (1082) ◽  
pp. 53-66 ◽  
Keyword(s):  
Electron Microscope ◽  
Staining Technique ◽  
Adductor Muscle ◽  
Uranyl Acetate ◽  
Acetate Solution ◽  
Left Handed ◽  
Thick Filaments ◽  
Crassostrea Angulata ◽  
Regular Arrangement ◽  
Made In

Observations of the surface of intact thick filaments from the oyster Crassostrea angulata have been made in the electron microscope. The surface structure has been revealed by metal shadowing and by a negative staining technique in which aqueous uranyl acetate solution is applied to filaments which have been rendered impervious to this solution. Both methods reveal a regular arrangement of round objects on the filament, interpreted as groups of myosin heads. The arrangement is that of the Bear-Selby net, probably with two or three myosin molecules per node. The possibility is discussed that the helical strands which give rise to the Bear-Selby net may occur in right- and left-handed forms in different filaments.

scholarly journals Abstract P-40: The Shape and Size of the Recombinant Virus-like Particles Were Checked by Means of Electron Microscope

2021 ◽  
Vol 11 (Suppl_1) ◽  
pp. S29-S30
Author(s):  
Ivan Okhrimenko ◽  
Yulia Zagryadskaya ◽  
Alexey Tsarenko ◽  
Valentin Borshchevskiy ◽  
Andrey Rogachev ◽  
...  
Keyword(s):  
Electron Microscope ◽  
De Novo ◽  
Fluorescent Proteins ◽  
Spherical Shape ◽  
Characteristic Size ◽  
Uranyl Acetate ◽  
Acetate Solution ◽  
Thin Carbon ◽  
Carbon Coated ◽  
Scientific Platform

Background: Nucleocapsid protein of hepatitis-B virus (HBcAg) recombinantly synthesized in prokaryotic and eukaryotic cells is known to be capable to self-assemble into highly immunogenic stable viral-like particles (VLP) of icosahedral shape with a characteristic size of 32 nm (Schödel et al., 1994; Murray and Shiau, 1999). The VLP formation is tolerant to the insertion of some artificial epitopes to N- and C-termini of HBcAg monomer and also into major insertion region (MIR), forming a spike on the surface of VLP (Tordjeman et al., 1993, Peyret et al., 2015). Methods: We have investigated the possibility of heterologous expression of de novo designed gene coding the first 148 amino acid residues of HBcAg (Pumpens and Grens, 1999). The gene was specially designed to be suitable for the insertions of genes coding fluorescent proteins, which are desired for the studies of VLP distribution in tissues by confocal microscopy. Gene was optimized for overexpression in E. coli producer strains and special attention was taken to obtain a simple purification scheme, which reliably reduces the amount of pyrogens in purified VLP. The MIPT scientific platform of electron microscopy equipped with the transmission electron microscope Tecnai Polara G2 (Thermo Scientific (FEI)) was used. Carbon-coated (Lacey Carbon and 10 nm thin carbon) copper 200 mesh grids were treated with glow-discharge and coated with VLP suspension in deionized water. The samples were stained with uranyl acetate solution, air-dried, and inspected at the accelerating voltage of 300 kV. Results: The 32 nm size of heterologously synthesized VLP was successfully proved, and spherical shape was seen using negative contrasting.

Electron microscopy of nocardial cell division

1978 ◽  
Vol 36 (2) ◽  
pp. 398-399
Author(s):  
Janet Hearn Woodward
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Uranyl Acetate ◽  
Potato Dextrose Agar ◽  
Transmission Electron ◽  
Noble Agar ◽  
Scanning Electron ◽  
Made In

Nocardia polychromogenes is an aerobic, gram (+), non-motile, partially acid-fast actinomycete with primary mycelia that fragment into bacillary and coccoid elements.For scanning electron microscopy, N. polychromogenes culture strain Waksman 3409-A was grown on Potato Dextrose Agar at 25 C for 12-72 h. Five mm2 sections of the colonies, including portions of the interior and perimeter were fixed by exposure to osmium fumes for 16-24 h and air dried for 2 h. Specimens, mounted on stubs and sputter coated with gold, were viewed in a Cambridge Stereoscan Mark II scanning electron microscope. For transmission electron microscopy, the organism was grown on Potato Dextrose Agar at 25 C for 12-32 h. Whole colonies, 1-2 mm in diameter, were fixed by exposure to osmium fumes for 24 h. After suspension in noble agar, cells taken from the periphery of the fixed colonies were stained with 0. 5% uranyl acetate made in acetate-veranol buffer.

Plasmalemma localisation of inorganic phosphate in B cells pancreas

1978 ◽  
Vol 36 (2) ◽  
pp. 528-529
Author(s):  
F. B. P. Wooding ◽  
K. Pedley ◽  
N. Freinkel ◽  
R. M. C. Dawson
Keyword(s):  
Electron Microscope ◽  
B Cells ◽  
B Cell ◽  
Pancreatic Islets ◽  
High Glucose ◽  
Lead Acetate ◽  
Inorganic Phosphate ◽  
Slight Modification ◽  
Uranyl Acetate ◽  
Lead Phosphate

Freinkel et al (1974) demonstrated that isolated perifused rat pancreatic islets reproduceably release up to 50% of their total inorganic phosphate when the concentration of glucose in the perifusion medium is raised.Using a slight modification of the Libanati and Tandler (1969) method for localising inorganic phosphate by fixation-precipitation with glutaraldehyde-lead acetate we can demonstrate there is a significant deposition of lead phosphate (identified by energy dispersive electron microscope microanalysis) at or on the plasmalemma of the B cell of the islets (Fig 1, 3). Islets after incubation in high glucose show very little precipitate at this or any other site (Fig 2). At higher magnification the precipitate seems to be intracellular (Fig 4) but since any use of osmium or uranyl acetate to increase membrane contrast removes the precipitate of lead phosphate it has not been possible to verify this as yet.

Sites of Adsorption of the Bacteriophages T3 and T5 on the Wall of Escherichia Coli B.

1967 ◽  
Vol 25 ◽  
pp. 96-97
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Electron Microscope ◽  
Uranyl Acetate ◽  
E Coli ◽  
Receptor Sites ◽  
Rigid Cell Wall ◽  
Host Cell Surface ◽  
Bacterial Viruses ◽  
Escherichia Coli B

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.

The Reaction of Brain Structures with OsO4-Zinc-Iodide Stain

1971 ◽  
Vol 29 ◽  
pp. 272-273
Author(s):  
Werner J. Niklowitz
Keyword(s):  
Electron Microscope ◽  
Structural Changes ◽  
Mossy Fiber ◽  
Toxic Metal ◽  
Staining Technique ◽  
Brain Structures ◽  
Oxidase Inhibitor ◽  
Fiber Layer ◽  
Hippocampal Tissue ◽  
Zinc Iodide

After intoxication of rabbits with certain substances such as convulsant agents (3-acetylpyridine), centrally acting drugs (reserpine), or toxic metal compounds (tetraethyl lead) a significant observation by phase microscope is the loss of contrast of the hippocampal mossy fiber layer. It has been suggested that this alteration, as well as changes seen with the electron microscope in the hippocampal mossy fiber boutons, may be related to a loss of neurotransmitters. The purpose of these experiments was to apply the OsO4-zinc-iodide staining technique to the study of these structural changes since it has been suggested that OsO4-zinc-iodide stain reacts with neurotransmitters (acetylcholine, catecholamines).Domestic New Zealand rabbits (2.5 to 3 kg) were used. Hippocampal tissue was removed from normal and experimental animals treated with 3-acetylpyridine (antimetabolite of nicotinamide), reserpine (anti- hypertensive/tranquilizer), or iproniazid (antidepressant/monamine oxidase inhibitor). After fixation in glutaraldehyde hippocampal tissue was treated with OsO4-zinc-iodide stain and further processed for phase and electron microscope studies.

Unusual Intranuclear Structures in Chick Sympathetic Neurons

1967 ◽  
Vol 25 ◽  
pp. 188-189
Author(s):  
E. B. Masurovsky ◽  
H. H. Benitez ◽  
M. R. Murray
Keyword(s):  
Electron Microscope ◽  
Sympathetic Neurons ◽  
Uranyl Acetate ◽  
Sympathetic Ganglia ◽  
Lead Citrate ◽  
Thin Sections ◽  
Cns Neurons ◽  
Mammalian Cns

Recent light- and electron microscope studies concerned with the effects of D2O on the development of chick sympathetic ganglia in long-term, organized culture revealed the presence of rod-like fibrillar formations, and associated granulofibrillar bodies, in the nuclei of control and deuterated neurons. Similar fibrillar formations have been reported in the nuclei of certain mammalian CNS neurons; however, related granulofibrillar bodies have not been previously described. Both kinds of intranuclear structures are observed in cultures fixed either in veronal acetate-buffered 2%OsO4 (pH 7. 4), or in 3.5% glutaraldehyde followed by post-osmication. Thin sections from such Epon-embedded cultures were stained with ethanolic uranyl acetate and basic lead citrate for viewing in the electron microscope.

Fine Structure of Interdental Cells in the Mouse Cochlea

1970 ◽  
Vol 28 ◽  
pp. 140-141
Author(s):  
Roberta M. Bruck
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Young Adult ◽  
Uranyl Acetate ◽  
Ground Substance ◽  
Tectorial Membrane ◽  
Lead Citrate ◽  
Unusual Structure ◽  
Thin Sections ◽  
Collagenous Fibers

An unusual structure in the cochlea is the spiral limbus; this periosteal tissue consists of stellate fibroblasts and collagenous fibers embedded in a translucent ground substance. The collagenous fibers are arranged in vertical columns (the auditory teeth of Haschke). Between the auditory teeth are interdental furrows in which the interdental cells are situated. These epithelial cells supposedly secrete the tectorial membrane.The fine structure of interdental cells in the rat was reported by Iurato (1962). Since the mouse appears to be different, a description of the fine structure of mouse interdental cells' is presented. Young adult C57BL/6J mice were perfused intervascularly with 1% paraformaldehyde/ 1.25% glutaraldehyde in .1M phosphate buffer (pH7.2-7.4). Intact cochlea were decalcified in .1M EDTA by the method of Baird (1967), postosmicated, dehydrated, and embedded in Araldite. Thin sections stained with uranyl acetate and lead citrate were examined in a Phillips EM-200 electron microscope.

Ultrastructural comparison of prolactin adenomas of pituitary in men and women

1988 ◽  
Vol 46 ◽  
pp. 346-347
Author(s):  
R.C. Caughey ◽  
U.P. Kalyan-Raman
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Phosphate Buffer ◽  
Pituitary Adenomas ◽  
Osmium Tetroxide ◽  
Secretory Granules ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Men And Women ◽  
Transmission Electron

Prolactin producing pituitary adenomas are ultrastructurally characterized by secretory granules varying in size (150-300nm), abundance of endoplasmic reticulum, and misplaced exocytosis. They are also subclassified as sparsely or densely granulated according to the amount of granules present. The hormone levels in men and women vary, being higher in men; so also the symptoms vary between both sexes. In order to understand this variation, we studied 21 prolactin producing pituitary adenomas by transmission electron microscope. This was out of a total of 80 pituitary adenomas. There were 6 men and 15 women in this group of 21 prolactinomas.All of the pituitary adenomas were fixed in 2.5% glutaraldehyde, rinsed in Millonig's phosphate buffer, and post fixed with 1% osmium tetroxide. They were then en bloc stained with 0.5% uranyl acetate, rinsed with Walpole's non-phosphate buffer, dehydrated with graded series of ethanols and embedded with Epon 812 epoxy resin.

Reconstruction of Two-Dimensional Projections of GP 32*I

1981 ◽  
Vol 39 ◽  
pp. 38-39
Author(s):  
H.A. Cohen ◽  
W. Chiu ◽  
J. Hosoda
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Uranyl Acetate ◽  
Distilled Water ◽  
Acetate Solution ◽  
Two Dimensional ◽  
Parent Molecule ◽  
T4 Bacteriophage ◽  
Electron Imaging ◽  
Better Than

GP 32 (molecular weight 35000) is a T4 bacteriophage protein that destabilizes the DNA helix. The fragment GP32*I (77% of the total weight), which destabilizes helices better than does the parent molecule, crystallizes as platelets thin enough for electron diffraction and electron imaging. In this paper we discuss the structure of this protein as revealed in images reconstructed from stained and unstained crystals.Crystals were prepared as previously described. Crystals for electron microscopy were pelleted from the buffer suspension, washed in distilled water, and resuspended in 1% glucose. Two lambda droplets were placed on grids over freshly evaporated carbon, allowed to sit for five minutes, and then were drained. Stained crystals were prepared the same way, except that prior to draining the droplet, two lambda of aqueous 1% uranyl acetate solution were applied for 20 seconds. Micrographs were produced using less than 2 e/Å2 for unstained crystals or less than 8 e/Å2 for stained crystals.

Sign in / Sign up

Export Citation Format

Share Document