Scanning and Transmission Electron Microscopy of Isolated Cells of Hydra littoralis

1972 ◽  
Vol 30 ◽  
pp. 160-161 ◽  
Author(s):  
Jane A. Westfall ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Osmium Tetroxide ◽  
Culture Medium ◽  
Sensory Cells ◽  
Isolated Cells ◽  
Sem And Tem ◽  
Transmission Electron ◽  
Cacodylate Buffer ◽  
Calcium And Magnesium Ions

Using scanning and transmission electron microscopy (SEM and TEM), we observed batteries of 20-30 nematocytes, cnidoblasts, sensory cells, and other neurons invaginated within epitheliomuscular cells of Hydra. In an attempt to determine how the cells were structurally interrelated, we isolated cells of Hydra littoralis for further study by SEM and TEM.To isolate cells, 30 Hydra littoralis were placed for 30 minutes in a P19 culture medium modified by omitting calcium and magnesium ions, adding 20% sucrose and stabilizing at pH 7.2 with sodium phosphate, then pipetted gently to free the epithelial cells from the mesoglea. Glutaraldehyde was added to make a 5% solution and the cells were fixed 1 hour at 0-4°C, centrifuged 10 minutes at 1000 X g, resuspended in cacodylate buffer twice, and placed 2 hours in 4% osmium tetroxide at 0-4°C.

Transmission Electron Microscopy of Lipid Vesicles for Drug Delivery: Comparison between Positive and Negative Staining

2010 ◽  
Vol 16 (4) ◽  
pp. 456-461 ◽  
Author(s):  
Valentina Bello ◽  
Giovanni Mattei ◽  
Paolo Mazzoldi ◽  
Nicoletta Vivenza ◽  
Paolo Gasco ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Drug Delivery ◽  
Transmission Electron Microscopy ◽  
Iron Oxide ◽  
Osmium Tetroxide ◽  
Lipid Vesicles ◽  
Negative Staining ◽  
Transmission Electron ◽  
Compositional Characterization

AbstractLipid-containing nanostructures, in the form of solid lipid nanoparticles or iron oxide nanoparticles (NPs) coated with a lipid shell, were used as case studies for assessing and optimizing staining for transmission electron microscopy structural and compositional characterization. These systems are of paramount importance as drug delivery systems or as bio-compatible contrast agents. In particular, we have treated the systems with a negative (phospshotungstic acid) or with a positive (osmium tetroxide) staining agent. For iron-oxide NPs coated with the lipid shell, negative staining was more efficient with respect to the positive one. Nevertheless, in particular cases the combination of the two staining procedures provided more complete morphological and compositional characterization of the particles.

scholarly journals Improved contrast in cytochemistry of dehydrogenases by scanning transmission electron microscopy.

1981 ◽  
Vol 29 (5) ◽  
pp. 678-681 ◽  
Author(s):  
W Deimann ◽  
R Freeman ◽  
H D Fahimi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Osmium Tetroxide ◽  
Lactic Dehydrogenase ◽  
Scanning Transmission Electron Microscope ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Tissue Contrast ◽  
Stem Image

A scanning transmission electron microscope (STEM) was used to examine ultrathin sections of rabbit white skeletal muscle. Lactic dehydrogenase (LDH) activity was localized in the tissue using the tetra-nitro blue tetrazolium (TNBT) method. For most specimens postfixation was omitted in order to avoid reoxidation and solubilization of the formazan by osmium tetroxide. The STEM image revealed sufficient contrast of the intracellular structures and apparently electron-dense reaction product in the sarcoplasmic reticulum and mitochondria. Substantially less contrast was obtained when the same areas were observed by conventional transmission electron microscopy (CTEM). In material postfixed with osmium tetroxide, although the tissue contrast was improved, the TNBT reaction product was focally leached out, exhibiting lower contrast than in unosmicated sections. These results indicate that the fine structural visualization of dehydrogenases with TNBT, the STEM technique as used in the present study is superior to that obtained by CTEM.

Scanning and Transmission Electron Microscopy of Isolated Cells from the Avian Salt Gland

1977 ◽  
Vol 35 ◽  
pp. 488-489
Author(s):  
Ian G. Thompson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Physiological Stress ◽  
Single Cells ◽  
Salt Gland ◽  
Secretory Cells ◽  
Surface Coat ◽  
Isolated Cells ◽  
Structural Differentiation ◽  
Transmission Electron

With the advent of new techniques for isolating single cells for biochemical and physiological investigation, an important consideration is the morphological integrity of these cells after dissociation from the intact tissue. Do isolated cells retain the degree of structural differentiation that is apparent in vivo? The principal secretory cells of the avian salt gland are an example of cells that are highly differentiated in form under conditions of physiological stress. This report describes the ultrastructure of dissociated salt gland cells as visualized with the scanning and transmission electron microscope.The dissociation procedure employed here was the same as that applied to the exocrine pancreas. For transmission electron microscopy the cell suspension was centrifuged and the resultant pellet prefixed in cacodylate buffered 3% glutaraldehyde- 1% paraformaldehyde, postfixed in unbuffered 1% osmium tetroxide, and embedded in epon-araldite. An assessment of the cell surface coat following enzymatic dissociation was facilitated by the inclusion of ruthenium red (500 ppm) in both the aldehyde and osmium fixation steps.

Characterization of mammary cells from the lactating rat by electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 560-561
Author(s):  
P. Sadhukhan ◽  
J. Chakraborty ◽  
M. S. Soloff ◽  
M. H. Wieder ◽  
D. Senitzer
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Types ◽  
Myoepithelial Cells ◽  
Mammary Tissue ◽  
Secretory Cells ◽  
Isolated Cells ◽  
Transmission Electron ◽  
Cell Processes ◽  
Phosphatase Cytochemistry

The means to identify cells isolated from the mammary gland of the lactating rat as a prerequisite for cell purification have been developed.The cells were isolated from mammary tissue with 0. 1% collagenase, and they were visualized by scanning and transmission electron microscopy and by alkaline phosphatase cytochemistry.The milk-secreting cells have surface microvilli, whereas the surface of the myoepithelial cells is smooth (Fig. 1). The two isolated epithelial cell types are readily distinguishable by transmission electron microscopy (Fig. 2). The secretory cells contain vacuoles and a relatively extensive rough endoplasmic reticulum, whereas the myoepithelial cells contain a more osmiophilic cytoplasm, contractile filaments (Fig. 3) and elongate processes. These features are consistent with the appearance of the two cell types in situ.Incubation of isolated cells with oxytocin prior to glutaraldehyde fixation resulted in the contraction of the myoepithelial cell processes (Figs. 4 & 5). This physiological response to oxytocin shows that the isolated myoepithelial cells were intact. The appearance of isolated secretory cells was unchanged by the presence of oxytocin.

Methods for preparation of cribellate spider silk fibrils for Transmission Electron Microscopy

1995 ◽  
Vol 53 ◽  
pp. 1076-1077
Author(s):  
B. Cutler
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Osmium Tetroxide ◽  
Spider Silk ◽  
Significant Component ◽  
Fixation Methods ◽  
Transmission Electron ◽  
Sputter Coating ◽  
Formaldehyde Exposure

Spider silk has been examined by transmission electron microscopy (TEM) for over 50 years. A later, more detailed study produced higher resolution images and included a discussion of fixation with osmium tetroxide (OSO4) vapor. The fixation resulted in only minor effects compared to unfixed specimens. Cribellate spiders produce a nonviscous adhesive silk that has as a significant component very fine fibrils produced by a structure called a cribellum. An opportunity to study cribellate silk in a spider family not previously investigated also led to a study of different fixation methods. Immature specimens of Titanoeca nigrella (Chamberlin) (Araneae, Titanoecidae) were collected under rocks at the Cimarron National Grasslands, Morton Co., Kansas. Spiders were kept in the laboratory and spun normal appearing webs. Copper and gold (for OSO4 treatments) 200 m grids were dragged through the webs. All combinations of treatments were used, but formaldehyde exposure always preceded OSO4 exposure which preceded sputter coating. Grids were examined with a JEOL 1200 EXII TEM. An accelerating voltage of 60kv and 100 um objective aperture were used for imaging.

The role of endoplasmic reticulum during gametogenesis in the aquatic fungus Allomyces macrogynus

1991 ◽  
Vol 69 (2) ◽  
pp. 336-341 ◽  
Author(s):  
Tommy C. Sewall ◽  
Jeffrey C. Pommerville
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Osmium Tetroxide ◽  
Cleavage Furrow ◽  
Aquatic Fungus ◽  
Transmission Electron ◽  
Allomyces Macrogynus ◽  
Zinc Iodide

The Chytridiomycete Allomyces macrogynus generates new membranes for cleavage furrow and nuclear-cap formation during gametogenesis and zoosporogenesis. Transmission electron microscopy after impregnation with a mixture of zinc iodide and osmium tetroxide clearly demonstrated changes in the endoplasmic reticulum. Endoplasmic reticulum was intensely stained but did not appear to contribute to the formation of the unstained flagellar membranes or cleavage furrows. However, the relative cytoplasmic volume of endoplasmic reticulum decreased as positively stained nuclear-cap membrane formed. These observations are consistent with the hypothesis that flagellar membranes and cleavage furrows are derived from trans-Golgi equivalents, whereas the nuclear-cap membrane is derived from the endoplasmic reticulum. Key words: Allomyces macrogynus, Chytridiomycetes, endoplasmic reticulum, gametogenesis, zoosporogenesis.

Characterization of Ustilago Hordei Fimbriae Using Scanning Transmission Electron Microscopy and Immunocytochemistry

1997 ◽  
Vol 3 (S2) ◽  
pp. 123-124
Author(s):  
Caroll E. Henry ◽  
T.L. Salaam ◽  
E. Steward-Clark ◽  
Joyce Craig ◽  
Lennell Reynolds
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Protein Concentration ◽  
Uranyl Acetate ◽  
Type I ◽  
Transmission Electron ◽  
Ustilago Hordei ◽  
Cacodylate Buffer ◽  
Scanning Transmission

Sporidia of Ustilago hordei produce surface fimbriae which are important in conjugation and pathogenicity. This work focuses on fimbrial origin and production using transmission electron microscopy (TEM) and immunocytochemistry.Wild type I4A sporidial cells cultured to log phase with rotary shaking in yeast extract glucose (YEG) growth for 48 h. at 21° C, were harvested by centrifugation at 8000 rpm, placed on formvar coated grids, negatively stained with 2% uranyl acetate and photographed in the JEOL 1200 STEM. Some cells were prepared for sectioning by fixation with gluteraldehyde and cacodylate buffer, post fixed in osmium tetroxide, dehydrated and embedded in epoxy and stained with uranyl acetate. The remainder of the cells were sheared in a blender to remove fimbriae. The defimbriated cells and 1 ml. of fimbrial suspension were presented to TEM. The rest of the fimbrial suspension was centrifuged at 30,000 rpm and he fimbrial pellet protein concentration was determined to be 1.345 nm. as assayed by UV adsorption.

Elektronenmikroskopische Untersuchungen am Geruchsorgan von Ophicephalus ( Channa) obscurus GUENTHER, 1861 (Teleostei, Ophicephalidae) / Electron Microscopical Studies of Olfactory Organ of Ophicephalus (Channa) obscurus GUENTHER, 1861 (Teleostei, Ophicephalidae)

1977 ◽  
Vol 32 (3-4) ◽  
pp. 307-308 ◽  
Author(s):  
Erhard Schulte ◽  
Rüdiger Riehl
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Olfactory Organ ◽  
Sensory Cells ◽  
Receptor Cells ◽  
Transmission Electron ◽  
Electron Microscopical ◽  
Primary Sensory Cells

Abstract The regio olfactoria of Ophicephalus was studied by transmission electron microscopy. Two types of receptor cells were found: ciliary receptor cells and microvillous receptor cells. Both of these types represent primary sensory cells. So one can regard the light microscopical findings of Kapoor and Ojha as disproved.

scholarly journals Cationic Fluorescent Nanogel Thermometers based on Thermoresponsive Poly(N-isopropylacrylamide) and Environment-Sensitive Benzofurazan

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1305 ◽  
Author(s):  
Teruyuki Hayashi ◽  
Kyoko Kawamoto ◽  
Noriko Inada ◽  
Seiichi Uchiyama
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Change ◽  
Culture Medium ◽  
Fluorescence Enhancement ◽  
Carcinoma Cells ◽  
Temperature Dependent ◽  
Medium Temperature ◽  
Mild Conditions ◽  
Transmission Electron

Cationic nanogels of N-isopropylacrylamide (NIPAM), including NIPAM-based cationic fluorescent nanogel thermometers, were synthesized with a cationic radical initiator previously developed in our laboratory. These cationic nanogels were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential measurements and fluorescence spectroscopy, as summarized in the temperature-dependent fluorescence response based on the structural change in polyNIPAM units in aqueous solutions. Cellular experiments using HeLa (human epithelial carcinoma) cells demonstrated that NIPAM-based cationic fluorescent nanogel thermometers can spontaneously enter the cells under mild conditions (at 25 °C for 20 min) and can show significant fluorescence enhancement without cytotoxicity with increasing culture medium temperature. The combination of the ability to enter cells and non-cytotoxicity is the most important advantage of cationic fluorescent nanogel thermometers compared with other types of fluorescent polymeric thermometers, i.e., anionic nanogel thermometers and cationic/anionic linear polymeric thermometers.

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