scholarly journals A New Universal Acrylic Embedding Resin for Both Light and Electron Microcopy

1994 ◽  
Vol 2 (4) ◽  
pp. 21-22
Author(s):  
Donald P. Cox
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Light Scattering ◽  
Tissue Structure ◽  
Original Structure ◽  
Plant Tissues ◽  
List Type ◽  
Type Number ◽  
Tissue Specimen ◽  
Low Viscosity

Successful immunolabeling in electron microscopy of animal and plant tissues requires a combination of excellent antigen preservation while maintaining the original structure of the tissue. One important element is tissue embedding which accomplishes two goals for the immunohistochemist, the preservation of tissue specimen structure and maintenance of biological antigenicity. Tissue embedding in plastic resins is a common method in which several important elements must be considered.1.Fine tissue structure must not be damaged by the polymerization.2.The plastic must be stable to the electron beam.3.Light scattering properties of the plastic should be minimal.4.The plastic should cut easily.5.The plastic must be of sufficiently low viscosity to infiltrate the tissue.

Modification of Pineal Ultrastructure by Exogenous Hormones

1967 ◽  
Vol 25 ◽  
pp. 170-171
Author(s):  
R. A. Turner ◽  
A. E. Rodin ◽  
D. K. Roberts
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Estradiol Benzoate ◽  
Female Rats ◽  
List Type ◽  
Type Number ◽  
Pregnant Rats ◽  
Gonadal Atrophy ◽  
Pineal Ultrastructure

There have been many reports which establish a relationship between the pineal and sexual structures, including gonadal hypertrophy after pinealectomy, and gonadal atrophy after injection of pineal homogenates or of melatonin. In order to further delineate this relationship the pineals from 5 groups of female rats were studied by electron microscopy:ControlsPregnant ratsAfter 4 weekly injections of 0.1 mg. estradiol benzoate.After 8 daily injections of 150 mcgm. melatonin (pineal hormone).After 8 daily injections of 3 mg. serotonin (melatonin precursor).No ultrastructural differences were evident between the control, and the pregnancy and melatonin groups. However, the estradiol injected animals exhibited a marked increase in the amount and size of rough endoplasmic reticulum within the pineal cells.

scholarly journals Preparation of Protein a Gold

1997 ◽  
Vol 5 (5) ◽  
pp. 12-13
Author(s):  
Paul Webster
Keyword(s):  
Electron Microscopy ◽  
Biological Activity ◽  
Colloidal Gold ◽  
Protein A ◽  
List Type ◽  
Type Number ◽  
Stained Glass ◽  
Small Particles ◽  
Silver Enhancement ◽  
Gold Particles

Colloidal gold has been used for centuries in the preparation of stained glass for windows and fine glassware. In recent years, colloidal gold particles have become a useful tool in microscopy for staining tissues and sections. Colloidal gold particles are especially useful for biological electron microscopy, Some of the reasons why are listed below.*Homogeneous preparations of particles varying in size from 3μm to 20μm can be easily prepared.*Colloidal gold suspensions are inexpensive to prepare. Most proteins can be easily coupled to colloidal gold particles.*Most proteins can be easily coupled to colloidal gold particles.*Proteins coupled to gold particles do not appear to lose their biological activity.*The colloidal gold particles can be easily seen in the electron microscope.*Colloidal gold does not naturally occur in biological material. Therefore, if you see it, it is because you put it there.*Colloidal gold probes can be used for light microscopy, The larger gold particles can be directly observed by the light microscope. Small particles are detected by silver enhancement or epipolarized illumination.*The same probes can be used for both LM and TEM imrnunocytochemistry.

scholarly journals Embedding Cultured Cells Grown in Well Plates

2006 ◽  
Vol 14 (3) ◽  
pp. 50-52
Author(s):  
Leona Cohen-Gould
Keyword(s):  
Electron Microscopy ◽  
Cross Sections ◽  
Cultured Cells ◽  
List Type ◽  
Type Number ◽  
Razor Blade ◽  
Cell Monolayers ◽  
Block Face ◽  
Resin Mixture

For years, I have used a hybrid Epon-analog resin to embed in culture dishes. I use a standard Epon formula but utilize the following components: LX-112 and DMP-30 from Ladd Research Industries DDSA and NMA from Electron Microscopy Sciences I know it seems weird, but years ago I tried all sorts things, from the “straight” formulations from each vendor to a bunch of mixtures. This one has never reacted with the plastic of the dishes. Here is how I do the actual embedding of the cell monolayers in the dishes:1)After the last 100% ethanol, remove the alcohol and cover the bottom of the well with a layer of resin mixture that is about 2 mm deep.2)Insert embedding tubes that are made by cutting the pyramidal bottoms off of BEEM capsules (just slice them with a fresh razor blade and be sure to insert them so that the manufactured end rather than the cut one is sitting against the dish).3)After inserting labels into the tubes, put them into the oven at 60° overnight.4)In the morning, fill just the embedding tubes and return everything to the oven again to finish polymerizing.5)When the resin is cured, grab the tubes with a pair of needlenosed pliers and snap them out. Sometimes a bit of the bottom of the dish comes away with the block, but often a very smooth block face results. If some of the dish comes up, it is easy to see under a dissecting microscope, and the dish portion comes away easily when trimming the block face.I often cut away part of the block face with a jeweler's saw, either to keep it in reserve or to re-embed it in order to get cross sections, and then trim the rest into a narrow rectangle.

Embedding resins: An historical perspective

1992 ◽  
Vol 50 (2) ◽  
pp. 1070-1071
Author(s):  
Hilton H. Mollenhauer
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Biological Material ◽  
Historical Perspective ◽  
Biological Applications ◽  
Low Viscosity ◽  
Divinyl Benzene ◽  
Matrix Substance ◽  
Improve Stability

There are several factors that were requisites for the biological applications of electron microscopy. One of these was, clearly, the development of a matrix substance that could infiltrate biological material and encapsulate tissue components so that they could be thin sectioned and examined under an electron beam. Without such matrix substances, examination of tissue as we know it today, would not be possible.Perhaps the start of practical electron microscopy in the context stated above was the application of methacrylate resins for tissue embedment. Methacrylates have a very low viscosity and maintain this viscosity until polymerization is initiated (for days or weeks if one should wish). The two most commonly used methacrylates were n-butyl (soft) and n-methyl (hard) which could be mixed in various proportions to yield almost any block hardness. Methacrylates can be cross-linked with divinyl benzene to improve stability but this was not commonly done. Methacrylates are very easy to section which was an important aspect at the time since sectioning had to be done with glass knives.

A new method for searching intracellular stereo structures in plant tissues

1990 ◽  
Vol 48 (3) ◽  
pp. 720-721
Author(s):  
Yaqin Yao ◽  
Xuanli Jiang ◽  
Dongwei Hu
Keyword(s):  
Room Temperature ◽  
Plant Tissues ◽  
Specimen Preparation ◽  
List Type ◽  
Type Number ◽  
Cell Organelles ◽  
Mesophyll Cells ◽  
Thin Sections ◽  
Wheat Leaves ◽  
Ethanol Series

The procedure for specimen preparation consist of the following. 1.fixing the plant tissues routinely;2.washing the blocks thoroughly in PBS buffer;3.immersing the blocks in a PEG (polyethylene glycol 4000) series (50, 70, 90, 100%) and embedding in pure PEG at 50°C, and cooling slowly to room temperature;4.cutting into thin sections 5-10 nm thick by LKB-V microtome;5.washing the sections a few times in water, dehydrating in a graded ethanol series, and drying in a critical-point dryer using liquid CO2;6.sputter-coating with gold palladium; and7.investigating in a Hitachi S-450 scanning electron microscope.By this method, the distinct, uninjured intracellular stereo structures can be conveniently found without Joss of cell organelles. Moreover, there are advantages to studying their stereo relationships between various components of cells. Using wheat leaves, one can find chloroplasts, mitochondria, nuclei, nucleoli, and parts of the cytoskeleton system in the mesophyll cells and their sizes and distributions directly.

scholarly journals A Method for Preparing Difficult Plant Tissues for Light and Electron Microscopy

2015 ◽  
Vol 21 (4) ◽  
pp. 902-909 ◽  
Author(s):  
Peta L. Clode
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Plant Tissues ◽  
Chemical Fixation ◽  
High Quality ◽  
Plant Materials ◽  
Low Viscosity ◽  
Transmission Electron ◽  
Plant Sciences ◽  
Very High

AbstractAlthough the advent of microwave technologies has both improved and accelerated tissue processing for microscopy, there still remain many limitations in conventional chemical fixation, dehydration, embedding, and sectioning, particularly with regard to plant materials. The Proteaceae, a family of plants widely distributed in the Southern Hemisphere and well adapted to harsh climates and nutrient-poor soils, is a perfect example; the complexity of Proteaceae leaves means that almost no ultrastructural data are available as these are notoriously difficult to both infiltrate and section. Here, a step-by-step protocol is described that allows for the successful preparation ofBanksia prionotes(Australian Proteaceae) leaves for both light and transmission electron microscopy. The method, which applies a novel combination of vibratome sectioning, microwave processing and vacuum steps, and the utilization of an ultra low viscosity resin, results in highly reproducible, well-preserved, sectionable material from which very high-quality light and electron micrographs can be obtained. With this, cellular ultrastructure from the level of a leaf through to organelle substructure can be studied. This approach will be widely applicable, both within and outside of the plant sciences, and can be readily adapted to meet specific sample requirements and imaging needs.

A Study on the Occurrence of Gold in Unoxidized Carlin-Type Ores in China Using AEM, SEM-EDX and SXRF

1990 ◽  
Vol 48 (2) ◽  
pp. 414-415
Author(s):  
Liu Yongkang ◽  
Liu Shirong ◽  
Wan Guangquan ◽  
Zhou Lindi ◽  
Li Jilian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gold Mineralization ◽  
Analytical Electron Microscopy ◽  
List Type ◽  
Type Number ◽  
X Ray ◽  
Combined Use ◽  
Analytical Electron ◽  
Scanning Electron ◽  
Gold Bearing

The knowledge about the occurrence of gold is essential both to the explanation for the genesis of gold mineralization in its deposits and to the evaluation and exploration or even smelt process of its ores. It has been well known that the gold occurrence in the Carlin-type ores still remains a difficult question to be answered because of the tiny scale of its locality and its very low content.This paper reports the results of our analysis on some gold bearing minerals in the Carlin-type ores discovered during recent years in China with combined use of analytical electron microscopy (AEM), scanning electron microscopy-energy dispersive X ray spectrometry (SEM-EDX) and synchrotron X ray flourescence analysis (SXRF) techniques as following:(1) Some gold occurred as submicron size grains in the ores (see Photo 1-4 and Figure 1-3) with grain size generally less than 0.2 micron.(2) It has been found by AEM and SEM-EDX observation and SXRF analysis that gold occurred as micrograins embedded in the boundaries of clay or quartz minerals rather than, as said, entered the lattice or adhered as a covering film to the surface of clay minerals (see Figure 4).

scholarly journals A NEW EPOXY EMBEDMENT FOR ELECTRON MICROSCOPY

1962 ◽  
Vol 13 (3) ◽  
pp. 437-443 ◽  
Author(s):  
James A. Freeman ◽  
Ben O. Spurlock
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Curing Agent ◽  
High Magnification ◽  
Low Viscosity ◽  
Wide Range ◽  
Lead Hydroxide

A new epoxy embedding mixture has been developed utilizing Maraglas 655 and Cardolite NC-513 with benzyldimethylamine (BDMA) as a curing agent. This epoxy mixture permits cellular preservation comparable to that obtained with Epon 812, ease of preparation of tissues, a wide range of miscibility, low viscosity, and, most important, ease of sectioning on a Porter-Blum microtome. In contrast to Epon-812-embedded tissues, Maraglas-Cardolite-embedded tissues can be sectioned in large dimensions with ease and consistent results without "chatter." No background granularity is detectable with high magnification study of Maraglas-Cardolite-embedded tissues. This epoxy is readily stained with lead hydroxide and is relatively stable in the electron beam.

A comparative study of fixation and dehydration techniques for the preservation of conidial structures in fungi for SEM

1987 ◽  
Vol 45 ◽  
pp. 982-983
Author(s):  
Richard E. Edelmann ◽  
Margaret E. Hogan
Keyword(s):  
Electron Microscopy ◽  
Freeze Drying ◽  
List Type ◽  
Type Number ◽  
Improved Method ◽  
Physical Damage ◽  
Air Drying ◽  
Reproductive Structures ◽  
Critical Point Drying ◽  
Scanning Electron

Conventional preparative techniques for biological specimens For scanning electron microscopy (SEM), when used for Fungal specimens, involve immersion in fixation and dehydration solutions. This often results in physical damage to delicate reproductive structures. Attempts at eliminating this damage using OsO4 vapors as a fixative, followed by air drying, may also produce less than optimal results.In order to devise an improved method for preparing fungal specimens, several genera were selected for their very delicate aerial conidial structures, and were prepared using six different procedures. The various protocols were as Follows:1)Immersion Fixation in 1% paraformaldehyde, 2.5% glutaraldehyde in H2O, post-fixation with 2% OsO4, and critical point drying2)2% OsO4 (in H2O) vapor fixation and air drying3)2% OsO4 (in H2O) vapor fixation and freeze drying4)Powdered paraformaldehyde in a 6% relative humidity atmosphere vapor fixation and air drying5)Aqueous 5% paraformaldehyde/8% glutaraldehyde vapor fixation, and air drying6)Aqueous 5% paraFormaldehyde/8% glutaraldehyde vapor fixation, and freeze drying

Initial stages of electron beam-induced transformations in potassium β‴-Ferrite, KFe17O25

1990 ◽  
Vol 48 (4) ◽  
pp. 810-811
Author(s):  
J.L. Hutchison ◽  
Y. Matsui ◽  
F.J. Lincoln
Keyword(s):  
Electron Microscopy ◽  
Structural Changes ◽  
High Resolution Electron Microscopy ◽  
Hexagonal Structure ◽  
Atomic Level ◽  
Nominal Composition ◽  
List Type ◽  
Type Number ◽  
Resolution Electron ◽  
Topotactic Transformation

Potassium β’’’-ferrite, nominal composition KFe17O25 and isostructural with sodium β’’’- alumina, has a hexagonal structure consisting of spinel blocks (SB) separated by loosely packed conduction planes (CP) containing relatively mobile K+ cations. Various structural changes which occur during electron irradiation have been characterised by high resolution electron microscopy and may be summarised as follows:1Migration of K+ and O2−from the conduction planes, followed by2Frequent collapse of CP.3Topotactic transformation of the resulting multiply-twinned spinel layers to form broad laths of magnetite, Fe304.4Gradual growth of wüstite, Fe1-xO on exposed surfaces.We have examined KFe17O25 at 400 kV, using a JEOL 4000EX, the resolution (1.65 Å)being sufficient to resolve all cation rows along two main crystallographic directions, and We could thus monitor the earliest stages of structural transformation at the atomic level.

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