Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

Localization of Silver in the Spleen of Argyric Rats by Energy Dispersive X-Ray Analysis Coupled with Scanning and Transmission Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 504-506
Author(s):  
G. Pereira
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Computer Assisted ◽  
White Pulp ◽  
Reticular Cell ◽  
X Ray ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Previous electron microscopic observations of the spleen have revealed the white pulp to be completely separated from the extravasated blood in the surrounding marginal zone by a strategically-located, double layer of reticular cells ensheathing a coarse reticular fiber. Similarly, a single reticular cell layer has been observed to form a continuous investment for all white pulp capillaries. To test the significance of this apparent isolation of the splenic white pulp from the blood, the distribution and composition of silver deposits in the spleen of argyric rats were determined by transmission and scanning electron microscopy coupled with computer-assisted x-ray analysis.Young male albino rats were made argyric by supplying them for many months with drinking water to which 1.5gm per liter of silver nitrate had been added. Specimens from the spleens of control and argyric animals were prepared for conventional transmission electron microscopy by glutaraldehyde-osmium fixation. For scanning electron microscopy, other specimens were fixed in buffered glutaraldehyde, freeze-dried in vacuo, coated with a thin film of gold- palladium and examined in a Cambridge Stereoscan Mark II.

Caracterización microestructural del queso de Burgos mediante diferentes técnicas microscópicas / Microstructural characterization of Burgos cheese using different microscopy techniques

2000 ◽  
Vol 6 (2) ◽  
pp. 151-157 ◽  
Author(s):  
I. Hernando ◽  
I. Pérez-Munuera ◽  
M.A. Lluch
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Three Dimensional ◽  
Microstructural Characterization ◽  
Transmission Electron ◽  
Dimensional Network ◽  
Lining Structure ◽  
Cheese Microstructure ◽  
Microscopy Techniques ◽  
Scanning Electron

Electron microscopy has made a significant contribution to our knowledge of the structure of foods and the interaction among their components. In this paper, several electron microscopy techniques are applied to study the Burgos cheese microstructure. Burgos cheese samples fixed in glutaraldehyde and observed by scanning electron microscopy showed a continuous three-dimensional network of protein, with roundish empty spaces, which probably contained fat, whey or air in the original sample. Fixation in osmium tetroxide showed the distribution of fat, which is organized in globules (1-3 ltm in diameter). Water closely and uniformly interacting with proteins and the protein shells deposited around the fat globule membranes (0.2 pm thick) can be observed by cryo-scanning electron microscopy. Samples observed by transmission electron microscopy showed loosely or ' strongly aggregated proteins forming the continuous network. Furthermore, a core and lining structure were distinguished; this structure could be related to the presence of B-lactoglobulin. Finally, this technique allows observations of individual casein grains and the interstitial spaces among them.

Comparative morphology of zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussel sperm: light and electron microscopy

1996 ◽  
Vol 74 (5) ◽  
pp. 809-815 ◽  
Author(s):  
G. K. Walker ◽  
C. A. Edwards ◽  
M. G. Black
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dreissena Polymorpha ◽  
Osmium Tetroxide ◽  
Light And Electron Microscopy ◽  
Comparative Morphology ◽  
Dreissena Bugensis ◽  
Transmission Electron ◽  
Contrast Microscopy ◽  
Scanning Electron

Adult zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels were induced to release large quantities of live spermatozoa by the administration of 5-hydroxytryptamine (serotonin). Sperm were photographed alive using phase-contrast microscopy and were fixed subsequently with glutaraldehyde followed by osmium tetroxide for eventual examination by transmission or scanning electron microscopy. The sperm of both genera are of the ect-aquasperm type. Their overall dimensions and shape allow for easy discrimination at the light and scanning electron microscopy level. Transmission electron microscopy of the cells reveals a barrel-shaped nucleus in zebra mussel sperm and an elongated nucleus in quagga mussel sperm. In both species, an acrosome is cradled in a nuclear fossa. The ultrastructure of the acrosome and axial body, however, is distinctive for each species. The structures of the midpiece are shown, including a unique mitochondrial "skirt" that includes densely packed parallel cristae and extends in a narrow sheet from the mitochondria.

Visualization of the Structure of the Rat Oocyte by Scanning Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 608-609
Author(s):  
P. Bagavandoss
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Preparation Techniques ◽  
Scanning Electron ◽  
Single Ovary ◽  
Sem Studies

Mammalian oocytes have been well studied with the light and the transmission electron microscopes(1,2). Glutaraldehyde and osmium tetroxide, which offer excellent fixation have certain limitations when used for SEM studies of rat ovaries. These fixatives require very small specimens for penetration, but such small specimens provide only a few intact oocytes for SEM observations. However, for meaningful observation of the changes brought about by various hormone treatments on the oocytes, a maximum number of oocytes must be available frcm a single ovary. Also, aldehyde and OSO4 fixed tissues are not easy to cut into smooth halves. This report cctnmuni- cates preparation techniques that yield useful SEM of the oocyte and associated structures of rat ovaries.Rat ovaries were dissected out and immediately placed in Bouin's fluid for 24 hours at rocm temperature. After fixation each ovary was cut into two halves with a sharp blade and kept in 70% alcohol overnight.

The Application of Scanning Electron Microscopy in the Investigation of Human Gastrointestinal Pathology

1973 ◽  
Vol 31 ◽  
pp. 430-431
Author(s):  
S. Siew
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Three Dimensional ◽  
Morphological Characteristics ◽  
Significant Advance ◽  
Gastrointestinal Pathology ◽  
Transmission Electron ◽  
Three Dimensional Configuration ◽  
Scanning Electron

A significant advance in our knowledge of gastrointestinal pathology has been achieved through endoscopy of the accessible portions of the alimentary tract. This procedure has allowed the evaluation of morphological characteristics of the mucosa by means of direct viewing in situ and through microscopy (light and transmission electron) of biopsies taken from selected areas. The importance of examination of the three dimensional configuration of the mucosal surface has been recognized, particularly in the assessment of the intestinal villi in cases of malabsorption, where it is recommended that the biopsies should be examined first by means of the dissecting microscope. Therefore, there is an obvious indication here for scanning electron microscopy, with its far greater potential.

A Novel Method to Analyze the Deep Trench Capacitors in DRAM

2000 ◽  
Author(s):  
Jack Lee ◽  
Kuo-Hui Huang ◽  
Jen-Lang Lue
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Section ◽  
Three Dimensional ◽  
Top Down ◽  
Deep Trench ◽  
Etching Solution ◽  
Transmission Electron ◽  
Novel Method ◽  
Scanning Electron

Abstract A novel method has been developed to reveal the entire three dimensional (3D) deep trench (DT) capacitors for inspection in DRAM, especially NO capacitor dielectrics, ASG residues at corners, morphology etc., for process evaluation and failure analysis. It offers an alternative to conventional cross-section polishing, top down polishing or FIB milling methods. A DRAM chip was ground and polished down to a certain level from the chip backside. An etching solution was then applied to enhance the DTs appearance. 3D DTs can be inspected in scanning electron microscopy (SEM). The entire DTs or specific DT also can be lifted out for detailed investigation in transmission electron microscopy (TEM). The innovation of this technique is to provide a quick 3D observation in SEM, and much more flexibility to an entire DT inspection in TEM, which were not presented before.

The anatomy of the mature perithecium in Sordaria humana and its significance for fungal multicellular development

1985 ◽  
Vol 63 (2) ◽  
pp. 281-296 ◽  
Author(s):  
N. D. Read ◽  
A. Beckett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Three Dimensional ◽  
Space Filling ◽  
Multicellular Development ◽  
Ascospore Discharge ◽  
Freeze Dried ◽  
Basic Features ◽  
Scanning Electron

The three-dimensional anatomy of mature perithecia was studied by light and scanning electron microscopy. Freeze-fractured material which was cither frozen-hydrated or freeze-dried received particular attention. The results illustrate certain basic features of fungal multicellular development. All perithecial cellular elements have been classified as either hyphal (hyphallike) or coherent. Elements of the neck peridium, basal peridium, and centrum pseudoparenchyma are coherent. Other elements are hyphal (hyphallike). The internal hyphallike elements are tightly packed within the coherent tissues and surrounded by mucilage. The perithecial "cavity" does not contain empty spaces. All stages of ascus development were observed. Highly vacuolated, irregularly branched hymenial and lateral paraphyses are present and may function as space-making and space-filling structures within the perithecium. The periphyses differentiate into the neck peridium and probably also grip asci prior to ascospore discharge. The basal peridium has one layer and the neck peridium has two layers. The centrum pseudo-parenchyma is flattened in mature perithecia. Comparisons are made with the modes of development undergone by other organisms.

Cuticular Pores in a Marine Mite

1972 ◽  
Vol 30 ◽  
pp. 164-165
Author(s):  
John H. Crowe
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Epoxy Resin ◽  
Low Viscosity ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Several species of marine mites are known to possess elaborate cuticular pores, the function of which is not known (Newell, 1947). In the present investigation the fine structure of the cuticular pores in a Halacarid mite, Copidognathus curtusi was studied, with a view towards discovering the function of the pores.For scanning electron microscopy the animals were fixed in cacodylatebuffered glutaraldehyde, post-fixed in osmium, and freeze-dried. For transmission electron microscopy they were fixed as above, embedded in Spurr's low viscosity epoxy resin, and sectioned on diamond knives.C. curtusi was chosen for study because of the abundance of pores in its cuticle.

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