XVIII.—The Spermatozoon of the Spider BeetlePtinus tectusBoieldieu as seen by Light and Electron Microscopy

1951 ◽  
Vol 64 (3) ◽  
pp. 353-366 ◽  
Author(s):  
Jozef Dlugosz ◽  
John W. Harrold
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscope ◽  
Light And Electron Microscopy ◽  
Sperm Head ◽  
Central Axis

SynopsisThe mature Ptinid sperm examined under the light microscope is found to be specialised in that the chromatin is not contained within a sperm head but is distributed along a central axis. The migration of chromatin resembles that found in Coccids by Hughes-Schrader (1948). Surrounding the axis is a more flexible helical membrane extending the whole length of the sperm.Under the electron microscope the membrane appears to consist of eighteen or twenty thin fibres and two thick fibres with striated sheaths. Near the posterior end of the membrane the fibres are surrounded by a ring. The structure is simpler than that of mammalian and avian sperms examined by other workers with similar techniques. Under the electron microscope, stages in the migration of chromatin in the immature sperm show a number of discrete opaque bodies which may be chromosomes. The approximate dimensions of the various structures are given.

scholarly journals An Electron Microscope Study of Basophile Substances of Frozen-Dried Rat Liver

1958 ◽  
Vol 4 (3) ◽  
pp. 291-300 ◽  
Author(s):  
Henry Finck
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Rat Liver ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Freeze Drying ◽  
Light And Electron Microscopy ◽  
Enzyme Treatment ◽  
Dense Granules ◽  
Homogeneous Matrix

Small pieces of liver from rats subjected to different dietary regimes were fixed by freeze-drying, and postfixed by in vacuo heating and denaturation with alcohol. Specimens were digested with ribo- or deoxyribonuclease, and stained with gallocyanin-chromalum, azure II, the Feulgen procedure or alcoholic platinic tetrabromide. Some specimens were reserved as controls of the effects of enzyme treatment. Stained and unstained specimens were embedded in methacrylate and examined by light and electron microscopy. Basophilic and Feulgen-positive substances, after contact with watery reagents, were found by electron microscopy to exist as small dense granules embedded in a less dense homogeneous matrix, forming the walls of submicroscopic vacuoles. These granules were absent after digestion with nucleodepolymerases. In specimens (unstained, or stained with platinic tetrabromide) which had not passed through water, the dense (basophile) substances in nuclei and cytoplasm were found to exist, not as granules, but as ill defined submicroscopic concentrates which blended imperceptibly into the homogeneous matrix of the vacuolar walls. Objections to the use of stains for improving contrast conditions in electron microscopy of tissues are discussed, and it is concluded that the reagents do not necessarily produce the observed increases in contrast by selectively stabilizing certain structures. The concept of microsomes as pre-existing distinct morphological entities in intact (unhomogenized) cells is thought to be inconsistent with the distribution of basophile substances in frozen-dried liver.

scholarly journals AN ELECTRON MICROSCOPE STUDY OF THE EMBRYOLOGY OF THE INTERCALATED DISC IN THE HEART OF THE RABBIT

1957 ◽  
Vol 3 (2) ◽  
pp. 193-202 ◽  
Author(s):  
Alan R. Muir
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Cardiac Muscle ◽  
Microscope Study ◽  
Light Microscope ◽  
Electron Microscope Study ◽  
Muscle Cells ◽  
Intercalated Disc ◽  
Adult Cell ◽  
Embryonic Muscle

Prenatal and postnatal cardiac muscle from rabbits has been studied by electron microscopy, after osmium fixation and methacrylate embedding. The observations showed that 1. Cell membranes divide the muscle into cellular units from the youngest embryo which was studied (9½ days after coitus) until the adult state. 2. The embryonic muscle cells contain only one nucleus, whereas the adult cell may be multinucleated. 3. At all stages of development, wherever a myofibrillar axis crosses a cellular boundary, the myofilaments are interrupted by an intercalated disc. 4. With age, increase in size and complexity of the discs render them recognisable by the light microscope.

scholarly journals Individual microtubules viewed by immunofluorescence and electron microscopy in the same PtK2 cell

1978 ◽  
Vol 77 (3) ◽  
pp. R27 ◽  
Author(s):  
M Osborn ◽  
RE Webster ◽  
K Weber
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscope ◽  
Immunofluorescence Microscopy ◽  
Uranyl Acetate ◽  
Tubulin Antibodies ◽  
Ptk2 Cell ◽  
Cytoplasmic Microtubules ◽  
Triton X ◽  
Microtubular Structures

PtK2 cells were grown on gold grids and treated with Triton X-100 in a microtubule stabilizing buffer. The resulting cytoskeletons were fixed with glutaraldehyde and subjected to the indirect immunofluorescence procedure using monospecific tubulin antibodies. Grids were examined first by fluorescence microscopy, and the display of fluorescent cytoplasmic microtubules was recorded. The grids were then stained with uranyl acetate and the display of fibrous structures recorded by electron microscopy. Thus the display of cytoplasmic microtubular structures in the light microscope and the electron microscope can be compared within the same cytoskeleton. The results show a direct correspondence of the fluorescent fibers in the light microscope with uninterrupted fibers of diameter approximately 550 A in the electron microscope. This is the diameter reported for a single microtubule decorated around its circumference by two layers of antibody molecules. Thus under optimal conditions immunofluorescence microscopy can visualize individual microtubules.

scholarly journals Scanning Electron Microscopy Observations of Loa loa (Nematoda)

2020 ◽  
Vol 11 (2) ◽  
pp. 486-492
Author(s):  
Jens Anibal Juul ◽  
Vegard Asgeir Forsaa ◽  
Tor Paaske Utheim ◽  
Endre Willassen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Case Report ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Loa Loa ◽  
Scanning Electron

We present a case report of periocular Loa loa. The key feature of L. loa distinguishing it from other human filarial parasites are cuticular bosses, which are presented in images from a light microscope and a scanning electron microscope. The cuticular bosses could be divided into three subtypes not previously described.

Bridging the Resolution Gap: Correlated 3D Light and Electron Microscopic Analysis of Large Biological Structures

1999 ◽  
Vol 5 (S2) ◽  
pp. 526-527
Author(s):  
Maryann E. Martone
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Surface Area ◽  
Light Microscope ◽  
Microscopic Analysis ◽  
Electron Microscopic Analysis ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Biological Structures ◽  
Ganglion Neurons

One class of biological structures that has always presented special difficulties to scientists interested in quantitative analysis is comprised of extended structures that possess fine structural features. Examples of these structures include neuronal spiny dendrites and organelles such as the Golgi apparatus and endoplasmic reticulum. Such structures may extend 10's or even 100's of microns, a size range best visualized with the light microscope, yet possess fine structural detail on the order of nanometers that require the electron microscope to resolve. Quantitative information, such as surface area, volume and the micro-distribution of cellular constituents, is often required for the development of accurate structural models of cells and organelle systems and for assessing and characterizing changes due to experimental manipulation. Performing estimates of such quantities from light microscopic data can result in gross inaccuracies because the contribution to total morphometries of delicate features such as membrane undulations and excrescences can be quite significant. For example, in a recent study by Shoop et al, electron microscopic analysis of cultured chick ciliary ganglion neurons showed that spiny projections from the plasmalemma that were not well resolved in the light microscope effectively doubled the surface area of these neurons.While the resolution provided by the electron microscope has yet to be matched or replaced by light microscopic methods, one drawback of electron microscopic analysis has always been the relatively small sample size and limited 3D information that can be obtained from samples prepared for conventional transmission electron microscopy. Reconstruction from serial electron micrographs has provided one way to circumvent this latter problem, but remains one of the most technically demanding skills in electron microscopy. Another approach to 3D electron microscopic imaging is high voltage electron microscopy (HVEM). The greater accelerating voltages of HVEM's allows for the use of much thicker specimens than conventional transmission electron microscopes.

Mouse ovarian tissue vitrification on copper electron microscope grids versus slow freezing: a comparative ultrastructural study

2015 ◽  
Vol 27 (7) ◽  
pp. 1020 ◽  
Author(s):  
Ferda Topal-Celikkan ◽  
Sinan Ozkavukcu ◽  
Deniz Balci ◽  
Sibel Serin-Kilicoglu ◽  
Esra Atabenli-Erdemli
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Cancer Therapy ◽  
Ovarian Tissue ◽  
Light And Electron Microscopy ◽  
Slow Freezing ◽  
Ovarian Tissue Cryopreservation ◽  
Control Group ◽  
Primordial Follicles ◽  
User Friendly

There are many reasons, including cancer therapy, for premature ovarian failure and infertility. Oocyte, embryo and ovarian cryopreservation are current options for fertility preservation. Ovarian tissue cryopreservation is essential in patients whose cancer therapy cannot be delayed, including prepubertal girls, and is mostly performed using slow freezing. In the present study, mouse ovarian tissues were vitrified on copper electron microscope grids (n = 18) or conventionally slow frozen (n = 18). Post-thaw tissues were examined histologically using light and electron microscopy and compared with the control group. According to light microscopy observations, antral follicles were found to be better preserved with the slow freezing technique rather than vitrification. Electron microscopy revealed swollen mitochondria in the oocyte cytoplasm, condensations in the zona pellucida, breakages in the junctions of granulosa cells and vacuolisation in the extracellular space in pathologic follicles, which were relatively more frequent, in the vitrification group after thawing. These results indicate that ovarian slow freezing is preferable than vitrification on copper electron microscope grids, especially for larger follicles. Conversely, vitrification of ovarian pieces using cooper grids is user-friendly and provided good protection for primordial follicles and stromal cells. There is a need for further studies into advanced tissue vitrification techniques and carriers.

Cytology and ultrastructure of Thanatephorus cucumeris and related taxa of the Rhizoctonia complex

1977 ◽  
Vol 55 (18) ◽  
pp. 2419-2436 ◽  
Author(s):  
C. C. Tu ◽  
James W. Kimbrough ◽  
H. C. Aldrich
Keyword(s):  
Electron Microscopy ◽  
Light Microscope ◽  
Light And Electron Microscopy ◽  
Middle Layer ◽  
Ultrastructural Level ◽  
Aniline Blue ◽  
Diploid Nucleus ◽  
Thanatephorus Cucumeris ◽  
Light Microscope Level ◽  
Endoplasmic Reticula

Cytological studies on the vegetative hyphae of members of the Rhizoctonia complex and basidial structures of Thanatephorus cucumeris were performed with light and electron microscopy. Vegetative cells of Thanatephorus and Waitea proved to be multinucleate, whereas those of Uthatobasidium, Ceratobasidium, Athelia. and Botryobasidium are binucleate.Dolipore septa of Thanatephorus, Waitea, Uthatobasidium, and Ceratobasidium are visible with the light microscope when stained with aniline blue in glycerine. Ultrastructurally, pore caps in these genera consisted of two-layered unit membranes, forming cisternae with an electron-dense middle layer. Dolipore septa of Athelia (S. rolfsii) and Botryobasidium are not visible in aniline blue at the light microscope level. At the ultrastructural level, there was an additional cisternal membrane making up a pore cap of three membranes. The fine structure of nuclei, mitochondria, endoplasmic reticula, vacuoles, and other organelles in the basidial structures of T. cucumeris was essentially the same as in other basidiomycetes.Karyogamy of two haploid nuclei occurs in the young basidia of T. cucumeris. The nuclear envelopes of both haploid nuclei break at their adjacent sides and fuse to form a diploid nucleus. After a short interphase, meiosis occurs. No leptotene was observed at prophase I, but a synaptinemal complex was evident and six pairs of chromosomes were observed throughout pachytene, diplotene, and diakinesis. The nuclear envelope disappears at metaphase I and a spindle appears. The second meiotic division is equational. Most of the mature and discharged spores are uninucleate.

scholarly journals A tribute to Shinya Inoue and innovation in light microscopy

2004 ◽  
Vol 165 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Karen R. Dell ◽  
Ronald D. Vale
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Light Microscope ◽  
Light And Electron Microscopy ◽  
Single Molecules ◽  
Living Cells ◽  
Dynamic Processes ◽  
New Techniques

The 2003 International Prize for Biology was awarded to Shinya Inoue for his pioneering work in visualizing dynamic processes within living cells using the light microscope. He and his scientific descendants are now pushing light microscopy even further by developing new techniques such as imaging single molecules, visualizing processes in living animals, and correlating results from light and electron microscopy.

Mucilaginous film production by plant cells immobilised in a polyurethane or nylon matrix

1985 ◽  
Vol 63 (12) ◽  
pp. 2357-2363 ◽  
Author(s):  
M. J. C. Rhodes ◽  
R. J. Robins ◽  
R. J. Turner ◽  
J. I. Smith
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Plant Cells ◽  
The Matrix ◽  
Nylon Fibre ◽  
Scanning Electron

The surface features of plant cells immobilised in a matrix of either reticulated polyurethane foam or nylon fibre have been examined with the scanning electron microscope. It has been found that both cells and matrix are enveloped in a thin film, the appearance of which is very dependent on the method by which material is prepared for scanning electron microscopy. The structure is severely damaged by fixation and dehydration. Only in specimens examined in the frozen hydrated state is a structure seen compatible with that observed with the light microscope. From the way the appearance of the film is affected by different methods of preparation for the scanning electron microscope, it is suggested that the film is a hydrated mucilage. The importance of this film for the retention of cells within the matrix is discussed.

scholarly journals ELECTRON MICROSCOPY OF THE AMMONIACAL SILVER REACTION FOR HISTONES IN THE ERYTHROPOIETIC CELLS OF THE CHICK

1970 ◽  
Vol 45 (2) ◽  
pp. 235-245 ◽  
Author(s):  
Edith K. MacRae ◽  
Gerald D. Meetz
Keyword(s):  
Electron Microscopy ◽  
Stem Cells ◽  
Bone Marrow ◽  
Electron Microscope ◽  
Light Microscope ◽  
Color Difference ◽  
Erythroid Cell ◽  
Erythroid Cells ◽  
Cell Series ◽  
Ammoniacal Silver

The product of the postformalin ammoniacal silver reaction, which has been claimed to distinguish lysine-rich from arginine-rich histones with the light microscope on the basis of a color difference, was examined in developing erythroid cells of chick bone marrow with the electron microscope. Stem cells and early erythroblasts exhibit no, or little, ammoniacal silver reaction product, while small basophilic erythroblasts, polychromatophilic erythrocytes, and reticulocytes exhibit an increasing amount of reaction product as maturation proceeds. The reaction product is in the form of discrete electron-opaque particles associated with heterochromatin. The ammoniacal silver reaction in the erythroid cell series is interpreted as reflecting either the accumulation of newly synthesized arginine-rich histones or changes in the availability of reactive sites in preformed histones.

Sign in / Sign up

Export Citation Format

Share Document