EM Study of Isopod Hemocytes

1998 ◽  
Vol 4 (S2) ◽  
pp. 1138-1139
Author(s):  
G. M. Vernon ◽  
E. J. Rappa ◽  
W. C. Murray ◽  
R. Witkus

Crustacean hemocytes have been characterized on the basis of cell size and nature of cytoplasmic granules. Based on light microscopic morphological analysis and cytochemistry, investigators variously named the hemocyte types (agranular, small-granule, large granule, undifferentiated, hyaline cells, non-explosive, explosive granulocytes, etc.). In his study of the isopod Armadillidium vulgare Faso adopted the terminology of Benjamin and James and referred to the hemocytes as hyaline cells, semi-granulocytes and granulocytes.In the present investigation we have studied the hemocytes of two isopods, Oniscus asellus and Armadillidium nasatum, using transmission electron microscopy. Hemolymph was collected by penetrating the posterior dorsal exoskeleton of 20 animals of each genus with a microcapillary pipette and drawing 3-5μL per isopod. The samples were processed following a standard technique. Thin sections were collected on 300 mesh copper grids, counterstained with 2% aqueous uranyl acetate and lead citrate, and viewed with a JEOL 1010 electron microscope.

Author(s):  
John H. L. Watson ◽  
Jessica Goodwin ◽  
E. Osborne Coates

Biopsies of lung were taken at operation from a patient with semi-acute diffuse pulmonary infiltrates for study by TEM and SEM. Tissue by light microscopy showed non-caseating granulomas consistent with sarcoidosis. Clinical evidence suggested a hypersensitivity reaction related to inhalation of substance of undetermined nature. Samples were fixed in glutaraldehyde, cacodylate-buffered. They were critical point dried and coated with Au-Pd for SEM, and were handled appropriately for TEM in Araldite. Sections were contrasted with uranyl acetate and lead citrate.


Author(s):  
T. Ohkura ◽  
M. Takashio ◽  
T. Watanabe

The experiments which we report here were performed to show qualitatively the presence or abscence of Cu in the mesostroma of the chick embryo cornea stained with alcian blue 8GS. Strips of the cornea were fixed in a buffered glutaraldehyde solution (2.5%, pH 7.4) and coloured with alcian blue 8GS at pH 2.5. Tissue specimens were postosmicated, dehydrated and embedded in Epon. Tissue blocks for the conventional transmission electron microscopy were prepared without alcian blue treatment, and the thin sections were stained with uranyl acetate and/or lead citrate. Fig. la shows the mesostroma of 3rd day chick embryo cornea; filaments run in various directions, and reveal no visible periodicity. Interfibrillar substances can not be demonstrated by the conventional method of the electron staining. The alcian blue treatment reveals the interfibrillar substances, which stand out in contrast as shown in Fig. lb.


Author(s):  
R.H.M. Cross ◽  
A.N. Hodgson ◽  
R.T.F. Bernard

Uranyl acetate is routinely used in the staining of thin sections of biological tissue for transmission electron microscopy. Although many methods for its preparation and use have been described, there is seldom reference to the reasons for variations in concentration, solvent, storage time and staining time. Likewise, possible variations in the effects of staining under different conditions are largely ignored. In order to gain clarity on this issue an attempt has been made to test three variables (solvent, storage time and use in light or dark) under controlled experimental conditions.The tissues used for the experiment were the testis of a marine limpet, the gut epithelium of a fresh-water catfish, and the kidney of a rat; all of which were fixed and embedded by standard methods. The uranyl acetate solutions were prepared at the outset of the experiment and dispensed into small volumes and stored in the dark at 4°C until required.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

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).


Author(s):  
J. Cadoz ◽  
J. Castaing ◽  
J. Philibert

Plastic deformation of alumina has been much studied; basal slip occurs and dislocation structures have been investigated by transmission electron microscopy (T.E.M.) (1). Non basal slip has been observed (2); the prismatic glide system <1010> {1210} has been obtained by compression tests between 1400°C and 1800°C (3). Dislocations with <0110> burgers vector were identified using a 100 kV microscope(4).We describe the dislocation structures after prismatic slip, using high voltage T.E.M. which gives much information.Compression tests were performed at constant strainrate (∿10-4s-1); the maximum deformation reached was 0.03. Thin sections were cut from specimens deformed at 1450°C, either parallel to the glide plane or perpendicular to the glide direction. After mechanical thinning, foils were produced by ion bombardment. Details on experimental techniques can be obtained through reference (3).


2021 ◽  
Vol 123 (6) ◽  
pp. 151761
Author(s):  
Tasuku Hiroshige ◽  
Kei-Ichiro Uemura ◽  
Shingo Hirashima ◽  
Kiyosato Hino ◽  
Akinobu Togo ◽  
...  

Further experiments by transmission electron microscopy on thin sections of stainless steel deformed by small amounts have enabled extended dislocations to be observed directly. The arrangement and motion of whole and partial dislocations have been followed in detail. Many of the dislocations are found to have piled up against grain boundaries. Other observations include the formation of wide stacking faults, the interaction of dislocations with twin boundaries, and the formation of dislocations at thin edges of the foils. An estimate is made of the stacking-fault energy from a consideration of the stresses present, and the properties of the dislocations are found to be in agreement with those expected from a metal of low stacking-fault energy.


Clay Minerals ◽  
1987 ◽  
Vol 22 (2) ◽  
pp. 179-185 ◽  
Author(s):  
T. Imbert ◽  
A. Desprairies

AbstractTransmission electron microscopy of ultramicrotomed thin-sections of Pleistocene and Eocene glass shards revealed the neoformation of (i) illite and (ii) halloysite at the glass periphery. According to previous experimental studies, halloysite neoformation in marine environments can occur on glass shards deposited in Si-rich sediments; an excess of Ca tends to inhibit the reaction.


1981 ◽  
Vol 44 (335) ◽  
pp. 357-359 ◽  
Author(s):  
D. J. Barber

The advantages of polished ultra-thin sections (PUTS) in the study of very fine-grained materials, such as occur in some meteorites, have been illustrated by Fredriksson et al. (1978) whose technique is based on the earlier work of Beauchamp and WiUiford (1974). An essential feature of such methods for friable and heterogeneous materials is the use of a medium, usually an epoxy resin, to consolidate and partially impregnate them. Normally one polished side of the specimen is bonded to a glass slide during preparation, and the finished PUTS are integral with the slide on completion. PUTS are typically 2-5 microns in thickness.


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