Methylcellulose/uranyl acetate solution

2010 ◽  
Vol 2010 (3) ◽  
pp. pdb.rec12178-pdb.rec12178
Keyword(s):  
Uranyl Acetate ◽  
Acetate Solution

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.

Alkaline Dissociation Products of Lumbricus Terrestris Hemoglobin Viewed with the STEM

1981 ◽  
Vol 39 ◽  
pp. 434-435
Author(s):  
O. H. Kapp ◽  
M. Ohtsuki ◽  
N. Robin ◽  
S. N. Vinogradov ◽  
A. V. Crewe
Keyword(s):  
Carbon Film ◽  
Lumbricus Terrestris ◽  
Uranyl Acetate ◽  
Acetate Solution ◽  
Oxygen Carriers ◽  
Complex Molecules ◽  
Thin Carbon ◽  
Thin Carbon Film ◽  
Multiple Copies ◽  
Hill Coefficients

Annelid extracellular hemoglobins are among the largest known proteins (M.W = 3.9 x 106), and together with the hemocyanins are the largest known oxygen carriers. They display oxygen affinities generally higher than those o vertebrate hemoglobins with Hill coefficients ranging from slightly higher than unity to values as high as 5-6. These complex molecules are composed of multiple copies of as many as six different polypeptides and posse: approximately 150 hemes per molecule.The samples were diluted to 100-200 μg/ml with distilled water just before application to a thin carbon film (∽15 Å thick). One percent (w/v) uranyl acetate solution was used for negative staining for 2 minutes and dried in air. The specimens were examined with the high resolution STEM. Their general appearance is that of a hexagonal bilayer (Fig. 1), each layer consisting of six spheroidal subunits. The corner to corner hexagonal dimensic is approximately 300 Å and the bilayer thickness approximately 200 Å.

scholarly journals CONFIGURATION OF A FILAMENTOUS NETWORK IN THE AXOPLASM OF THE SQUID (LOLIGO PEALII L.) GIANT NERVE FIBER

1969 ◽  
Vol 43 (3) ◽  
pp. 480-505 ◽  
Author(s):  
J. Metuzals
Keyword(s):  
Nerve Fiber ◽  
Protein Structures ◽  
Three Dimensional ◽  
High Resolution Electron Microscopy ◽  
Uranyl Acetate ◽  
Nerve Fibers ◽  
Acetate Solution ◽  
Thin Sections ◽  
Resolution Electron ◽  
Specific Affinity

High-resolution electron microscopy is integrated with physicochemical methods in order to investigate the following preparations of the giant nerve fibers of the squid (Loligo pealii L.): (1) Thin sections of fibers fixed in four different fixatives; (2) fresh axoplasm stained negatively in solutions of different pH and composition; (3) chemically isolated threadlike elements of the axoplasm. A continuous, three-dimensional network can be identified in all these preparations of the axoplasm. The network is composed of coiled or looped unit-filaments ∼30 A wide. The unit-filaments are intercoiled in strands ∼ 70–250 A wide. The strands are oriented longitudinally in the axoplasm, often having a sinuous course and cross-associations. Microtubules are surrounded by intercoiled unit-filaments and filamentous strands. Calcium ions cause loosening and disintegration of the network configuration. UO2++ ions of a 1% uranyl acetate solution at pH 4.4 display a specific affinity for filamentous protein structures of the squid giant nerve fiber axoplasm, segregating the filamentous elements of the axoplasm in a coiled, threadlike preparation. The uranyl ions combine probably with the carboxyl groups of the main amino acids of the protein—glutamic and aspartic acids. It is proposed that by coiling/decoiling and folding/unfolding of the unit-filaments, shifts in physicochemical properties of the axoplasm are maintained.

scholarly journals Uranium Carbide Fibers with Nano-Grains as Starting Materials for ISOL Targets

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2458
Author(s):  
Sanjib Chowdhury ◽  
Leonor Maria ◽  
Adelaide Cruz ◽  
Dario Manara ◽  
Olivier Dieste-Blanco ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Uranyl Acetate ◽  
Slow Heating ◽  
Acetate Solution ◽  
Fiber Morphology ◽  
Uranium Carbide ◽  
C Fibers ◽  
Effective Contact ◽  
Viscous Solutions ◽  
Nano Grains

This paper presents an experimental study about the preparation, by electrospinning, of uranium carbide fibers with nanometric grain size. Viscous solutions of cellulose acetate and uranyl salts (acetate, acetylacetonate, and formate) on acetic acid and 2,4-pentanedione, adjusted to three different polymer concentrations, 10, 12.5, and 15 weight %, were used for electrospinning. Good quality precursor fibers were obtained from solutions with a 15% cellulose acetate concentration, the best ones being produced from the uranyl acetate solution. As-spun precursor fibers were then decomposed by slow heating until 823 K under argon, resulting in a mixture of nano-grained UO2 and C fibers. A last carboreduction was then carried out under vacuum at 2073 K for 2 h. The final material displayed UC2−y as the major phase, with grain sizes in the 4 nm–10 nm range. UO2+x was still present in moderate concentrations (~30 vol.%). This is due to uncomplete carboreduction that can be explained by the fiber morphology, limiting the effective contact between C and UO2 grains.

Ultrastructural and functional similarity of the haustorial neckband of rust fungi and the Casparian strip of vascular plants

1976 ◽  
Vol 54 (21) ◽  
pp. 2484-2489 ◽  
Author(s):  
Michèle C. Heath
Keyword(s):  
Parallel Evolution ◽  
Uranyl Acetate ◽  
Rust Fungi ◽  
Host Cells ◽  
Acetate Solution ◽  
Transport Barrier ◽  
Intact Cells ◽  
Casparian Strip ◽  
Disulphonic Acid ◽  
Endodermal Cells

In susceptible hosts infected with rust fungi, an osmiophilic band, bridging the interface between host and parasite, is usually observed about midway along the haustorial neck. This neckband bears certain ultrastructural resemblances to the Casparian strip of endodermal cells, and the possible similarity in function as a barrier to apoplastic transport was investigated using 4-acetamido, 4′-isothiocyanostilbene-2, 2′-disulphonic acid (SITS) and uranyl acetate solutions. Both these reagents appeared to travel along host and fungal walls but did not readily penetrate the protoplasts of either organism.When rust-infected cowpea leaves were infiltrated with SITS reagent, haustoria in broken cells fluoresced as brightly as the walls of both intercellular hyphae and host cells. Mature haustoria in intact cells, however, did not fluoresce, suggesting the presence of a barrier to the flow of reagent to the haustorium. When rusted corn leaves were allowed to take up uranyl acetate solution, the ultrastructural distribution of uranyl crystals indicated that this barrier was, indeed, the neckband, and additional circumstantial evidence for the function of this structure was provided by indications from both techniques that the transport barrier was absent from very young haustoria; the latter have previously been shown to lack an ultrastructurally detectable neckband during the early stages of their development.These results appear to confirm the functional, as well as morphological, similarity of the haustorial neckband and the Casparian strip, and these, therefore, present an unusual example of parallel evolution at the structural and functional level. The importance of such a barrier to apoplastic transport in haustoria-producing fungi is discussed.

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.

Ultrastructural Observations of the Rat Oocyte During the Estrous Cycle

1968 ◽  
Vol 26 ◽  
pp. 158-159
Author(s):  
I. M. Baccarini
Keyword(s):  
Electron Microscopy ◽  
Estrous Cycle ◽  
Uranyl Acetate ◽  
The Other ◽  
Osmic Acid ◽  
Acetate Solution ◽  
Lead Citrate ◽  
Vaginal Smears ◽  
Additional Information ◽  
Histochemical Methods

The cytological ultrastructure of the oocyte in different vertebrates and in insects has been described. Additional information on this subject is the purpose of this report which describes the findings on the oocyte of the rat during the estrous cycle.Vaginal smears were taken daily from 27 inbred Wistar-Furth rats to determine stages of the cycle. The animals were sacrificed with anesthesia in proestrous, estrous and metestrous and the ovaries removed surgically. In each case one ovary was used for electron microscopy and the other for histochemical methods.The ovary for electron microscopy was placed immediately into cold 3% phosphate-buffered glutaraldehyde for 2 hours and then into 1% phosphate-buffered osmic acid for 2-3 hours. The tissue was embedded in Durcupan ACM (FLUKA). The sections were double stained with 50% alcoholic uranyl acetate solution and with lead citrate.

Structural Investigation of Invertebrate Hemoglobins Using the Stem

1980 ◽  
Vol 38 ◽  
pp. 676-677
Author(s):  
O.H. Kapp ◽  
M. Ohtsuki ◽  
S.N. Vinogradov
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
Structural Investigation ◽  
Uranyl Acetate ◽  
Carbon Substrate ◽  
Distilled Water ◽  
Acetate Solution ◽  
Sedimentation Constant ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Polypeptide Chains

Scanning transmission electron microscopy (STEM) was used to study the structure of the extracellular hemoglobins of the annelids Lumbricus, Arenicola, and Nephtys. These are giant molecules, possessing a molecular weight of 3-4 x IO6,a sedimentation constant of about 60s and consisting of about five to seven different polypeptide chains (1,2,3). The samples were diluted to 100-200μg/ml with distilled water just before application to a very thin(∽15Å) carbon substrate supported on a microgrid. One percent (w/v) uranyl acetate solution was used for negative staining for 2 min. and dried in air. The specimens were examined with an electron energy of 22-35keV.

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.

Ultrastructural Study of Trophozoites and Cysts of Acanthamoeba-Hartmannella and Naegleria Species

1974 ◽  
Vol 32 ◽  
pp. 192-193
Author(s):  
A. Julio Martinez ◽  
Richard J. Duma ◽  
Doris G. Fultz ◽  
Ruth B. Finley
Keyword(s):  
Present Report ◽  
Uranyl Acetate ◽  
Osmic Acid ◽  
Acetate Solution ◽  
Lead Citrate ◽  
Thin Sections ◽  
Cacodylate Buffer ◽  
In Situ Fixation ◽  
Diamond Knife

Ultrastructural components of trophozoites and cysts of Acanthamoeba-Hartmannella (A-H) and Naegleria amebas have been investigated. The present report describes a technique to study the morphological features of such protozoa.The A-H strains selected were cultured for 7 days in axenic amebic media, and the Naegleria strains were cultured for 7 days in axenic media with blood. In situ fixation was accomplished by adding an equal volume of 4% Osmic Acid in Cacodylate buffer at 4¶C for one hour. Following frequent agitation, the tubes were then spun at 2500 RPM for 10 minutes to obtain a pellet. The pellets were dehydrated in graded series of alcohols (from 50% to absolute) and propylene oxide and then embedded in EPON. One micron sections were stained with Paragon (PS 1301) for thirty seconds. Thin sections were cut with a diamond knife, double stained with 5% alcoholic uranyl acetate solution and lead citrate and observed in an Hitachi-HS-8F2 electron microscope.

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