scholarly journals Araldite as an Embedding Medium for Electron Microscopy

1958 ◽  
Vol 4 (2) ◽  
pp. 191-194 ◽  
Author(s):  
Audrey M. Glauert ◽  
R. H. Glauert
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Thin Sectioning ◽  
Embedding Medium ◽  
Final Block

Epoxy resins are suitable media for embedding for electron microscopy, as they set uniformly with virtually no shrinkage. A mixture of araldite epoxy resins has been developed which is soluble in ethanol, and which yields a block of the required hardness for thin sectioning. The critical modifications to the conventional mixtures are the choice of a plasticized resin in conjunction with an aliphatic anhydride as the hardener. The hardness of the final block can be varied by incorporating additional plasticizer, and the rate of setting can be controlled by the use of an amine accelerator. The properties of the araldite mixture can be varied quite widely by adjusting the proportions of the various constituents. The procedure for embedding biological specimens is similar to that employed with methacrylates, although longer soaking times are recommended to ensure the complete penetration of the more viscous epoxy resin. An improvement in the preservation of the fine structure of a variety of specimens has already been reported, and a typical electron microgram illustrates the present paper.

Albumins as Embedding Media for Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 422-423 ◽  
Author(s):  
J. L. Farrant ◽  
J. D. McLean
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Temperature ◽  
Biological Material ◽  
Globular Proteins ◽  
The Past ◽  
Antibody Staining ◽  
Thin Sectioning ◽  
Embedding Medium

For electron microscope techniques such as ferritin-labeled antibody staining it would be advantageous to have available a simple means of thin sectioning biological material without subjecting it to lipid solvents, impregnation with plastic monomers and their subsequent polymerization. With this aim in view we have re-examined the use of protein as an embedding medium. Gelatin which has been used in the past is not very satisfactory both because of its fibrous nature and the high temperature necessary to keep its solutions fluid. We have found that globular proteins such as the serum and egg albumins can be cross-linked so as to yield blocks which are suitable for ultrathin sectioning.

Epoxy Resin Embedment

1968 ◽  
Vol 26 ◽  
pp. 100-101
Author(s):  
J. G. Adams ◽  
M. M. Campbell ◽  
H. Thomas ◽  
J. J. Ghldonl
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Epoxy Resin ◽  
Light Microscope ◽  
Epoxy Resins ◽  
Image Contrast ◽  
Tissue Preservation ◽  
Resin System ◽  
Excellent Quality

Since the introduction of epoxy resins as embedding material for electron microscopy, the list of new formulations and variations of widely accepted mixtures has grown rapidly. Described here is a resin system utilizing Maraglas 655, Dow D.E.R. 732, DDSA, and BDMA, which is a variation of the mixtures of Lockwood and Erlandson. In the development of the mixture, the Maraglas and the Dow resins were tested in 3 different volumetric proportions, 6:4, 7:3, and 8:2. Cutting qualities and characteristics of stability in the electron beam and image contrast were evaluated for these epoxy mixtures with anhydride (DDSA) to epoxy ratios of 0.4, 0.55, and 0.7. Each mixture was polymerized overnight at 60°C with 2% and 3% BDMA.Although the differences among the test resins were slight in terms of cutting ease, general tissue preservation, and stability in the beam, the 7:3 Maraglas to D.E.R. 732 ratio at an anhydride to epoxy ratio of 0.55 polymerized with 3% BDMA proved to be most consistent. The resulting plastic is relatively hard and somewhat brittle which necessitates trimming and facing the block slowly and cautiously to avoid chipping. Sections up to about 2 microns in thickness can be cut and stained with any of several light microscope stains and excellent quality light photomicrographs can be taken of such sections (Fig. 1).

The Application of Ultra-Thin Sectioning Techniques to Non-Biological Samples

1968 ◽  
Vol 26 ◽  
pp. 332-333
Author(s):  
C. F. Oster
Keyword(s):  
Biological Sciences ◽  
Epoxy Resin ◽  
Cross Sections ◽  
Biological Samples ◽  
Industrial Applications ◽  
Photographic Film ◽  
Silver Particles ◽  
Thin Sectioning ◽  
Embedding Medium

Although ultra-thin sectioning techniques are widely used in the biological sciences, their applications are somewhat less popular but very useful in industrial applications. This presentation will review several specific applications where ultra-thin sectioning techniques have proven invaluable.The preparation of samples for sectioning usually involves embedding in an epoxy resin. Araldite 6005 Resin and Hardener are mixed so that the hardness of the embedding medium matches that of the sample to reduce any distortion of the sample during the sectioning process. No dehydration series are needed to prepare our usual samples for embedding, but some types require hardening and staining steps. The embedded samples are sectioned with either a prototype of a Porter-Blum Microtome or an LKB Ultrotome III. Both instruments are equipped with diamond knives.In the study of photographic film, the distribution of the developed silver particles through the layer is important to the image tone and/or scattering power. Also, the morphology of the developed silver is an important factor, and cross sections will show this structure.

scholarly journals An Effective Method of Preparing Sections of Bacillus polymyxa Sporangia and Spores for Electron Microscopy

1960 ◽  
Vol 7 (2) ◽  
pp. 373-376 ◽  
Author(s):  
Pauline E. Holbert
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Electron Micrographs ◽  
Epoxy Resins ◽  
Bacillus Polymyxa ◽  
Thin Sections ◽  
Similar Images ◽  
Embedding Medium ◽  
First Time ◽  
Diamond Knife

Bacillus polymyxa sporangia and spores were prepared for examination in the electron microscope by methods whose critical features were apparently: judicious use of vacuum, to encourage complete penetration of the embedding medium; the use of epoxy resins as embedding media; and cutting of the thin sections with a diamond knife. Electron micrographs of material prepared in this manner exhibit undeformed sporangial sections. Some of the structures revealed have been shown before, though perhaps less distinctly; other structures are revealed here for the first time. While this single study does not pretend to elucidate all the complexities of sporulation in bacteria, these and similar images should make this possible, and some mention of the preparatory techniques that lead to them seems advisable at this time.

Eponate 12, a new epoxy resin: Comparisons with EPON 812 and observations on its use for general biological electron microscopy

1987 ◽  
Vol 45 ◽  
pp. 628-629
Author(s):  
J.A. Mascorro ◽  
G.S. Kirby
Keyword(s):  
Electron Microscopy ◽  
Epoxy Resin ◽  
Flow Rate ◽  
Epoxy Resins ◽  
Physical Characteristics ◽  
Past Study ◽  
Chemical Company ◽  
Shell Chemical

Many epoxy resins have been introduced during the last several years as replacements for Epon 812 since the Shell Chemical Company discontinued production of this popular embedding resin. In a past study, the present investigators examined several of the “replacement” resins for physical characteristics such as viscosity, flow rate, density, mass weight, and hardness of the polymerized medium. In addition, other equally important parameters including sectioning and infiltrating character as well as stain-ability and section strength subsequent to beam and vacuum conditions also were evaluated. The present work follows a similar rationale and seeks to determine this same information for Eponate 12, an epoxy resin designated as a true generic replacement for the formerly available Epon 812 product.For purposes of physical comparisons, Eponate 12 was tested against a sample of original Shell Epon 812 still maintained in our laboratory.

Water Containing Epon 812/815 Embedding Method for Electron Microscopy

1980 ◽  
Vol 38 ◽  
pp. 642-643
Author(s):  
Yoshiya Shinagawa ◽  
Yasuko Shlnagawa ◽  
Sadao Uchida
Keyword(s):  
Electron Microscopy ◽  
Epoxy Resins ◽  
Embedding Method ◽  
Thin Sectioning

The special types of epoxy resins such as Durcupan or Quetol 651 have been used as water-miscible embedding media for electron microscopy hitherto. However, difficulties exist in handling of these resins, especially in thin-sectioning. We have developed a method of polymerization of the conventional epoxy resins, Epon 812, 815 (Shell Co.) and Luveak 812 (Nakarai Co.) in the presence of water. The authorsl) previously reported melamine resins as water-containing embedding media which have been recently sold by Nakarai Co. as Luveak A and B. The melamine resins as well as aldehyde or urea resins have atypical electron staining. The water-containing epoxy resins embedding method in this report provides usual electron staining and facile sectioning like as the traditional Epon embedding method. Negatively stained micrograph in part is obtained in this method (Fig. la).

A study of the fracture surface of cured epoxy resin

1983 ◽  
Vol 41 ◽  
pp. 34-35
Author(s):  
V. B. Gupta ◽  
L. T. Drzal ◽  
Y. L. Chen
Keyword(s):  
Electron Microscopy ◽  
Epoxy Resin ◽  
Size Distribution ◽  
Epoxy Resins ◽  
Crosslink Density ◽  
Fracture Behavior ◽  
Fracture Pattern ◽  
Area Of Interest ◽  
Transmission Electron ◽  
Wide Size Distribution

The dependence of the fracture behavior of cured epoxy resin on its morphology is an area of interest and controversy. It is believed that the resin is heterogeneous, comprising spherical entities of high crosslink density in a matrix of relatively lower crosslink density. These heterogeneities have quite a wide size distribution, predominantly in the 10 to 50nm range and are believed to be aggregates of a few elementary entities of around 5nm in diameter. Since the fracture pattern has been observed to be around the boundary of the aggregate rather than through it, it is important to understand how these larger entities influence the fracture behavior. Hence the present study was designed to map the size distribution of aggregates which will henceforth be referred to as nodules. Although it has been pointed out that scanning electron microscopy is more suited for the study of polymer fractography than transmission electron microscopy, there has been a much greater use of TEM employing the replica method in morphological investigations of cured epoxy resins. It will be shown here that if suitable specimens are used, the morphology of cured epoxy resins can be studied with SEM.

Three dimensional fine structure of the capillary terminals in the red pulp of the human spleen

1978 ◽  
Vol 36 (2) ◽  
pp. 468-469
Author(s):  
Teruo Suzuki ◽  
Susumu Shimizu ◽  
Yoshiaki Hataba ◽  
Yuji Kirino
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fine Structure ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Human Spleen ◽  
Perfusion Fixation ◽  
Embedding Medium ◽  
Scanning Electron ◽  
Red Pulp

Introduction In spite of the efforts of many researchers, three dimensional fine structure of the capillary terminals in the red pulp of the spleen has not been successively demonstrated up to date. By stereoscopic scanning electron microscopy of a perfusion-fixed and freeze-fractured dog spleen, we have recently demonstrated that the terminals of the cordal capillaries are obviously open in the cordal labyrinth.Material and Methods In the human spleen, however, applications of the same method only was not necessarily successful to obtain unquestionable informations on their three dimensional structure, since it is very difficult to flush out blood cells thoroughly from the cordal labyrinth at the time of the perfusion fixation. In the present study, a synthetical observation of the capillary terminals in the red pulp of the normal human spleen was undertaken by three ways of; 1) transmission electron microscopy of ultrathin sections (TEM), 2) scanning electron microscopy of freeze-fractured tissue (FF-SEM), and 3) scanning electron microscopy of serial sections from which the embedding medium was removed (SS-SEM).

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