Resin embedding

Luft J H 1961 Improvements in epoxy resin embedding methods J. Biophys. Biochem. Cytol. 9 409-14... 

Lauchli, A., Spurr, A.R. Wittkop, R.W. (1970). Electron probe analysis of freeze substituted, epoxy resin embedded tissue for ion transport studies in plants. Planta, 95, 341-50. 

S5mthetic resin-embedded alfalfa samples were oven dried at 65 °C for 24 h and cut at 40-90 nm. The slides were analyzed using a JEOL 2010-F TEM prepared with field emission gun, EDS, and a high angle annular dark field detector for the analysis of solitary nanoparticles. 

The residue produced from the 350°C run contained discernible resinite particles. In contrast, examination of the fluorescence of residues from the two 370° runs in blue light showed that little resinite was left undissolved other than that incorporated within a matrix of other macerals. Instead, a diffuse fluorescence had been imparted to the epoxy resin embedding medium. Presumably, the epoxy was able to dissolve some of the liquefied resin remaining after extraction with ethyl acetate. In the residue from the run at 400°C, only one discrete resinite particle was observed among the many coal particles embedded in the epoxy polymer. It appears that in a short time at 350°, most, but not all, of the resinite undergoes liquefaction. All other material in the sample needs considerably more severe treatment. 

Spurr, A.R. (1969). A low-viscosity epoxy resin embedding medium for electron microscopy. Journal of Ultrastructural Research 26 31. 

Danscher, C., and Rytter-Norgaard, (1983) Light microscropic visualization of colloidal gold on resin-embedded tissue./. Histochem. Cytochem. 31, 1394-1398. 

Sections for lightmicroscope radioautography originate either from par-affin/paraplast or, more recently, resin-embedded specimens as mentioned. 

Prior DAM, Oparka KJ, Roberts IM. En bloc optical sectioning of resin-embedded specimens using a confocal laser scanning microscope. JMicrosc 1998 193 20-27. 

Protocol for Preparing Light Microscopic Radioautographs from Resin-Embedded Tissues (Adapted from Morel [7])... 

Herman EM. Colloidal gold labeling of acrylic resin embedded plant tissues, in Colloidal Gold Methods and Applications, Vol. 2, (Hayat MA, ed.), Academic Press, New York, 1989, pp. 303-321. 

In a previous review of this topic (5), it was suggested that molecular distillation drying followed by resin embedding needed more work before it could be evaluated as a preparative technique for microanaly-tical work as there had only been one investigation that had used it (59). Unfortunately, as far as this author is aware, there has only been one more study (12) that has used the technique to prepare material for micro-analysis. It is possible that workers have been put off using it by the apparent fall from grace of the related freeze substitution technique or, more likely, by the expense of molecular distillation drying apparatus. 

If epoxy resin-embedded tissue is used, cut 2- jm-thick sections with a glass knife, mount on APES-coated slides, and dry as described in Note 2. Deplasticize the sections by immersing them in sodium eth(meth)oxide for 15 min (8). Wash the sections twice with equal parts of methanol (or IMS) and xylene, twice with methanol, for 3 min each, and rehydrate. Afterward, the same HIER and immuno-histochemical protocols are employed as in paraffin sections. 

Epoxy resin-embedded semithin sections of 1-2 j,m may also be used following extraction of the resin with a sodium meth(et)hoxide treatment for 5-8 min. Sodium meth(et)hoxide is prepared by saturating methanol or ethanol with sodium hydroxide pellets. 

Fixation by rapid freezing followed by either freeze substitution or cryosectioning can also overcome some of the problems of standard immersion fixation and resin embedding. These are more specialized techniques and will not be dealt with here. Discussion of the methods can be found in Polak and Varndell (6), Hayat (7), and Verkleij and Leunissen (8). 

FIGURE 1.1. Electron micrographs of liver tissue processed differently for transmission electron microscopy. (A) Processed by the conventional method. Note superior quality of ultrastructural preservation compared with that obtained with microwave heating. (B) Rapidly processed by vacuum microwave heating. The whole process from tissue fixation to resin embedding was completed in 2 hr. The quality of ultrastructural preservation is satisfactory. Magnification 6,21 Ox (B). (B) courtesy of Richard T. Giberson. 

Heating is effective in antigen retrieval on semithin and thin sections of resin-embedded tissues. This results not only from the breakdown of protein crosslinks introduced by aldehyde but also from the breakage of bonds between the epoxy resin and the embedded tissue (see Fig. 7.2). It is known that epoxy resins form covalent bonds with tissue proteins during embedding. 

MICROWAVE HEAT-ASSISTED IMMUNOLABELING OF RESIN-EMBEDDED SECTIONS... 

Labeling in the microwave oven is usually carried out at 37°C for 15 min. Longer durations and higher temperatures may result in undesirable changes in antibody concentration and molarity of the salts and pH. After heat treatment, the sections should be kept at room temperature for at least 2 min to stabilize the antibody-antigen complexes. The step-by-step procedure for microwave heat-assisted immunolabeling of resin-embedded thin sections for electron microscopy follows (Rangell and Keller, 2000) ... 

Sormunen, R., and Leong, A. S.-Y. 1998. Microwave-stimulated antigen retrieval for immunohistol-ogy and immunoelectron microscopy of resin-embedded sections. Appl. Immunohistochem. 6 234-237. 

FIGURE 4.3 High magnification transmission electron micrographs of multilamellar membrane structures in the intercellular space of the cornified part of human epidermis. (A) cryo-electron micrograph of vitreous section. (B, C) conventional electron micrographs of resin embedded sections. The cell plasma membranes appear as 3.8 nm wide bilayers in (A) (open white arrow). A 16 nm broad zone of electron dense material, the cornified cell envelope (white asterix), is directly apposed to the cytoplasmic side of the bilayer plasma membranes in the native sample (A) (open white arrow). Scale bar 50 nm (A). Scale bars 25 nm (B, C) adapted from measures given in Swartzendruber et al. (1989). (A) reprinted from Norlen (2003). With permission from Blackwell Science Publications. (B, C) reprinted from Swartzendruber et al. (1989). With permission from Blackwell Science Publications. 

The classic solution is the application of current and voltage transformers, usually as a cast resin embedded type. As a certain disadvantage of inductive transducers, their small frequency range may be considered. Other solutions for current sensors are Rogowski coils (with active or passive integrators) or the fibre-optic current sensor, based upon the Faraday effect [20]. 

Kojima Y, Yoon SY, Kayama T (1988b) A study of production of CTMP from hardwood Part 3 Characterization of pulps produced by CTMP O-i process J Jpn Tappi 42 953-962 Lange PW (1954) The distribution of lignin in the cell wall of normal and reaction wood from spruce and a few hardwoods Sven Papperstidn 57 525-532 Luft JH (1961) Improvements in epoxy resin embedding method J Biophys Biochem Cytol 9 409-414... 

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