Preparation of Ultrathin Sections of Polymeric Materials

1963 ◽  
Vol 36 (3) ◽  
pp. 799-802
Author(s):  
K. Kh. Razikov ◽  
G. S. Markova
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Electron Diffraction ◽  
Present Article ◽  
Ultrathin Section ◽  
Polymeric Materials ◽  
Thermal Regulation ◽  
Polymeric Fibers ◽  
Thin Sections ◽  
Ultrathin Sections

Abstract Much importance attaches at the present time to the use of ultrathin sections for the investigation of the structure of polymeric materials by electron microscopy, electron diffraction and other methods. Extremely thin sections (down to hundredths of a micron) can be prepared by means of ultramicrotomes in which thermal regulation of the feed of the specimen is provided. The use of ultramicrotomes in various branches of sciences has given valuable information on the fine structure of many substances. In the present article we describe the use of the ultrathin section method for the investigation of the structure of polymers by means of an ultramicrotome of the “Sjostrand Ultra-microtome LKB-Producter” type. As a result of the elasticity of polymeric materials the preparation of thin sections is rendered difficult. Therefore the development of a method of producing ultrathin sections of polymeric materials is of considerable interest. We have developed such a method for the study of the structure of thin polymeric fibers (of diameter 15 to 20 µ) of thick monofilament (of diameter 0.5 mm and above) and also of films. The technique of preparation of ultrathin sections consists of the following stages: 1) embedding the specimens for investigation; 2) preparation of the specimen for cutting; 3) preparation of the knives; and 4) preparation of the apparatus and cutting.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

scholarly journals STUDIES ON THE MODE OF ACTION OF EXCESS OF VITAMIN A

1963 ◽  
Vol 17 (1) ◽  
pp. 111-121 ◽  
Author(s):  
Audrey M. Glauert ◽  
Mary R. Daniel ◽  
J. A. Lucy ◽  
J. T. Dingle
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Vitamin A ◽  
Phase Contrast ◽  
Phase Contrast Microscopy ◽  
Intact Cells ◽  
Thin Sections ◽  
Initial Effect ◽  
Contrast Microscopy ◽  
Site Of Action

Rabbit erythrocytes have been haemolysed by treatment with vitamin A alcohol and the sequence of changes in the fine structure of the cells during lysis has been investigated by phase contrast microscopy of intact cells and electron microscopy of thin sections. The initial effect of the vitamin, which occurs within 1 minute, is the production of cells of bizarre appearance which have a greatly increased surface area relative to untreated cells. Large indentations appear in the surfaces of the cells, and vacuoles are formed from the indentations by a process that resembles micropinocytosis. The cells then become spherical and loss of haemoglobin begins as breaks appear in the membranes of some cells; finally, ghosts are produced that are no longer spherical but still contain numerous vacuoles. These observations support the thesis that one site of action of vitamin A is at lipoprotein membranes.

The fine structure of Sphaerotilus nutans

1973 ◽  
Vol 19 (3) ◽  
pp. 309-313 ◽  
Author(s):  
Judith F. M. Hoeniger ◽  
H.-D. Tauschel ◽  
J. L. Stokes
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Lateral Position ◽  
Thin Sections ◽  
Liquid Cultures ◽  
Sphaerotilus Natans ◽  
Stationary Liquid ◽  
Basal Disk ◽  
Polar Organelle

Sphaerotilus natans developed sheathed filaments in stationary liquid cultures and motile swarm cells in shaken ones. Electron microscopy of negatively stained preparations and thin sections showed that the sheath consists of fibrils. When the filaments were grown in broth with glucose added, the sheath was much thicker and the cells were packed with granules of poly-β-hydroxybutyrate.Swarm cells possess a subpolar tuft of 10 to 30 flagella and a polar organelle which is usually inserted in a lateral position and believed to be ribbon-shaped. The polar organelle consists of an inner layer joined by spokes to an accentuated plasma membrane. The flagellar hook terminates in a basal disk, consisting of two rings, which is connected by a central rod to a second basal disk.

scholarly journals OBSERVATIONS ON THE FINE STRUCTURE OF THE MACRONUCLEUS OF TOKOPHRYA INFUSIONUM

1955 ◽  
Vol 1 (5) ◽  
pp. 421-428 ◽  
Author(s):  
Maria A. Rudzinska ◽  
Keith R. Porter
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Cross Sections ◽  
Regular Structure ◽  
Metaphase Chromosomes ◽  
Thin Sections ◽  
Significant Aspect ◽  
Parallel Lines ◽  
Chromatin Material ◽  
First Time

The macronucleus in Tokophrya infusionum is composed of numerous Feulgen-positive chromatin bodies (about 0.5 µ in diameter) which appear in thin sections as a dense spongework, homogeneous throughout. The same appearance characterizes metaphase chromosomes of higher forms. Some chromatin bodies of the macronucleus were found to possess a highly organized structure in certain old organisms. This structure appears in cross-sections as a honeycomb and in longitudinal sections as parallel lines about 120 A in diameter evenly spaced (about 230 A). As far as is known this is the first time a regular structure has been found in bodies of chromosomal character at the dimensional level presently explored by electron microscopy. The demonstration that OsO4 can preserve order in chromatin material is another significant aspect of these findings.

scholarly journals Further Observations on the Fine Structure of Chrysochromulina Ericina Parke & Manton

1961 ◽  
Vol 41 (1) ◽  
pp. 145-155 ◽  
Author(s):  
I. Manton ◽  
G. F. Leedale
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Cell Surface ◽  
Light Microscopy ◽  
Flat Plate ◽  
Outer Layer ◽  
Living Cells ◽  
Layered Plates ◽  
Thin Sections ◽  
Micro Anatomy

C. ericina Parke & Manton has been re-investigated to add salient features of micro-anatomy from the electron microscopy of thin sections and also to add photographs of living cells taken with anoptral contrast light microscopy.The most important new observations concern the scales which are shown to be essentially two-layered plates in which the layers in the very large spined scales have become separated except at their edges, with the outer layer greatly hypertrophied to produce a hollow spine with a flared base closed at the bottom by a flat plate. The patterns of external marking on the two layers are very similar in both plate-scales and spines in this species and the orientation of both with respect to the cell surface has been demonstrated by a section of the scales in situ.

scholarly journals Caracteres estructurales y ultraestructurales de la gametogénesis de Chara hydropitys (Charophyceae)

2017 ◽  
Vol 65 (4) ◽  
pp. 1507
Author(s):  
Edgar Javier Rincón Barón ◽  
Yenny Magaly Castrillón Bolaños ◽  
Gerardo Andrés Torres ◽  
Fernando Alzate Guarin ◽  
Silvia Espinosa Matías
Keyword(s):  
Electron Microscopy ◽  
Chromatin Condensation ◽  
Side Wall ◽  
Flagellar Apparatus ◽  
Cytoplasmic Inclusions ◽  
Thin Sections ◽  
Transmission Electron ◽  
Structural Details ◽  
Entire Cell ◽  
Ultrathin Sections

In Charophyceae, the oosporangia and antheridia are the respective female and male structures of sexual reproduction. These organs are characterized by their morphological complexity and usefulness in taxonomy and systematics. Here we described the structural and ultraestructural details of Chara hydropitys gametogenesis. The fertile material from the algae was collected in a tributary stream of the Río Meléndez in Cali, Colombia (3º21´23´´N - 76º32´5.2´´W) in March 2011. The specimens were fixed and processed following the standard protocols for inclusion in resin. Thin sections (0.3-0.5 μm) were stained with toluidine O, and were observed by photonic microscopy, and additional ultrathin sections (60-90 nm) were observed by transmission electron microscopy (TEM); other samples were processed and observed by scanning electron microscopy (SEM). We found that the oosporangia are covered with spiral cells, forming 10-12 convolutions and ends in five coronula cells. The immature oosporangia wall is formed by two layers that correspond to the wall of the spiral cells and to the oosphere. In mature stages, the oosporangia wall is composed by six additional layers, three of them are provided by the oosphere and the other three are provided by the spiral cells. Oosphere size increases progressively while the spiral cells grow and divide. The cytoplasm of the immature oosphere does not exhibit conspicuous cytoplasmic inclusions, nevertheless, with the maturation, the number of starch granules increases, occupying most of the cell volume. In the spiral cells of the mature oosporangia we observed large number of chloroplast with starch accumulations, between thylakoid lamellae and a vacuole that occupies almost the entire cell. By using SEM it was possible to appreciate, that the external wall of the oospore, more accurately, on the fossa area, shows verrucose micro-ornamentations with verrucae elevations. In mature antheridia, shield cells are strongly pigmented orange due to the presence of a large number of plastoglobules between thylakoid lamellae. The spermatogenous filaments are developed from cells of the secondary capitulum; those, by unidirectional and sincronic mitotic divisions develop the spermatocytes. The biflagellate antherozoids are developed from the haploid cells by spermiogenesis. The subcellular events related with these division and differentiation processes, include first, chromatin condensation, loss of nucleoli and more activity in dictyosomes. Subsequently, retracts the cytoplasm and the organelles are aligned along the condensed nucleus and flagellar apparatus. Mature antherozoids emerge through a side wall pore of the spermatocytes. All the described events showed that the gametogenesis processes and the gametes structural details in general, are widely conserved in this algae group.

Electron microscopic analysis of objects in light microscopic sections

1978 ◽  
Vol 36 (2) ◽  
pp. 80-81
Author(s):  
Arvid B. Maunsbach
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Microscopic Analysis ◽  
Electron Microscopic Level ◽  
Semithin Section ◽  
Cover Glass ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Glass Slides ◽  
Ultrathin Sections

Structural studies in experimental biology or in pathology are frequently extended from the light to the electron microscopic level. This is often done by cutting both semithin (about 1 μm) and thin sections from the same tissue block after embedding for electron microscopy. However, in many studies it would be of great value to analyse the same structure both by light and electron microscopy, i.e. to be able to study by electron microscopy an object which is first detected by light microscopy in a semithin section. To achieve this, a method has been developed by which ultrathin sections are cut directly from the semithin section containing the object of interest.Semithin sections, about 1 μ in thickness, are cut from Epon or Vestopal embedded tissue. The sections are placed on ordinary glass slides and stained with toluidine blue. The sections are studied in the light microscope without a cover glass or mounted in water.

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.

scholarly journals THE FINE STRUCTURE OF THE NUCLEOLUS DURING MITOSIS IN THE GRASSHOPPER NEUROBLAST CELL

1965 ◽  
Vol 24 (3) ◽  
pp. 349-368 ◽  
Author(s):  
Barbara J. Stevens
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Light Microscope ◽  
Light And Electron Microscopy ◽  
Peripheral Zone ◽  
Structural Components ◽  
Thin Sections ◽  
Nucleolar Material ◽  
Central Regions ◽  
Homogeneous Background

The behavior of the nucleolus during mitosis was studied by electron microscopy in neuroblast cells of the grasshopper embryo, Chortophaga viridifasciata. Living neuroblast cells were observed in the light microscope, and their mitotic stages were identified and recorded. The cells were fixed and embedded; alternate thick and thin sections were made for light and electron microscopy. The interphase nucleolus consists of two fine structural components arranged in separate zones. Concentrations of 150 A granules form a dense peripheral zone, while the central regions are composed of a homogeneous background substance. Observations show that nucleolar dissolution in prophase occurs in two steps with a preliminary loss of the background substance followed by a dispersal of the granules. Nucleolar material reappears at anaphase as small clumps or layers at the chromosome surfaces. These later form into definite bodies, which disappear as the nucleolus grows in telophase. Evidence suggests both a collecting and a synthesizing role for the nucleolus-associated chromatin. The final, mature nucleolar form is produced by a rearrangement of the fine structural components and an increase in their mass.

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