scholarly journals Embedding Cultured Cells Grown in Well Plates

2006 ◽  
Vol 14 (3) ◽  
pp. 50-52
Author(s):  
Leona Cohen-Gould

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.

Author(s):  
R. A. Turner ◽  
A. E. Rodin ◽  
D. K. Roberts

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.


1997 ◽  
Vol 5 (5) ◽  
pp. 12-13
Author(s):  
Paul Webster

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.


1980 ◽  
Vol 28 (2) ◽  
pp. 178-180 ◽  
Author(s):  
K Kawamoto ◽  
A Hirano ◽  
F Herz

The use of xylene for the easy separation of cultured cells embedded in situ from their plastic growth surface is described. This step simplifies the preparation of cell monolayers for electron microscopy.


1994 ◽  
Vol 2 (4) ◽  
pp. 21-22
Author(s):  
Donald P. Cox

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.


Author(s):  
K. Chien ◽  
R. Van de Velde ◽  
R. Heusser

The localization of an area of interest for ultramicrotomy within a tissue block is usually determined by first surveying large thick sections under the light microscope. Yang has shown that multiple areas from a large block face can be vertically divided for sequential sectioning. By applying a simple and direct technique, two or more areas of interest from the same block can be sectioned simultaneously and examined on one grid for ultrastructural studies.Depending on the size and distance between the areas that are going to be sectioned, there are several possible approaches:1.Two Small Areas Widely Separated. Since the entire surface of the block is in one plane after thick sectioning, it is possible to rotate the block and trim selected areas into two trapezoids so that their leading and trailing edges are parallel to the knife edge. If their combined total areas do no exceed the average area routinely sectioned, the two trapezoids can be cut simultaneously and two ribbons formed (fig.1).


2018 ◽  
Author(s):  
Tin Ki Tsang ◽  
Eric A. Bushong ◽  
Daniela Boassa ◽  
Junru Hu ◽  
Benedetto Romoli ◽  
...  

ABSTRACTElectron microscopy (EM) offers unparalleled power to study cell substructures at the nanoscale. Cryofixation by high-pressure freezing offers optimal morphological preservation, as it captures cellular structures instantaneously in their near-native states. However, the applicability of cryofixation is limited by its incompatibilities with diaminobenzidine labeling using genetic EM tags and the high-contrast en bloc staining required for serial block-face scanning electron microscopy (SBEM). In addition, it is challenging to perform correlated light and electron microscopy (CLEM) with cryofixed samples. Consequently, these powerful methods cannot be applied to address questions requiring optimal morphological preservation and high temporal resolution. Here we developed an approach that overcomes these limitations; it enables genetically labeled, cryofixed samples to be characterized with SBEM and 3D CLEM. Our approach is broadly applicable, as demonstrated in cultured cells, Drosophila olfactory organ and mouse brain. This optimization exploits the potential of cryofixation, allowing quality ultrastructural preservation for diverse EM applications.


Author(s):  
Liu Yongkang ◽  
Liu Shirong ◽  
Wan Guangquan ◽  
Zhou Lindi ◽  
Li Jilian ◽  
...  

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).


eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Tin Ki Tsang ◽  
Eric A Bushong ◽  
Daniela Boassa ◽  
Junru Hu ◽  
Benedetto Romoli ◽  
...  

Electron microscopy (EM) offers unparalleled power to study cell substructures at the nanoscale. Cryofixation by high-pressure freezing offers optimal morphological preservation, as it captures cellular structures instantaneously in their near-native state. However, the applicability of cryofixation is limited by its incompatibility with diaminobenzidine labeling using genetic EM tags and the high-contrast en bloc staining required for serial block-face scanning electron microscopy (SBEM). In addition, it is challenging to perform correlated light and electron microscopy (CLEM) with cryofixed samples. Consequently, these powerful methods cannot be applied to address questions requiring optimal morphological preservation. Here, we developed an approach that overcomes these limitations; it enables genetically labeled, cryofixed samples to be characterized with SBEM and 3D CLEM. Our approach is broadly applicable, as demonstrated in cultured cells, Drosophila olfactory organ and mouse brain. This optimization exploits the potential of cryofixation, allowing for quality ultrastructural preservation for diverse EM applications.


Author(s):  
Richard E. Edelmann ◽  
Margaret E. Hogan

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


Author(s):  
J.L. Hutchison ◽  
Y. Matsui ◽  
F.J. Lincoln

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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