Freeze embedding

Small pieces of tissue (approx. 5 mm) are quickly frozen with or without freeze-embedding medium (e.g.,Tissue Tek Miles Laboratories) and stored at 80°C until analysed. 

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. 

Compound (Miles Laboratories, Elkhart, IN), snap-frozen, and cut into sections for comparison with paraffin-embedded cell sections (3) FFPE Cell Blocks Six cell pellets were fixed in 10% neutral buffered formalin immediately after harvest, at room temperature for 6,12,24h, 3,7, and 30 days, respectively. For further comparison with the cell model system, recently collected sample of human breast cancer tissues were processed by OCT-embedding and snap-freezing the corresponding routine FFPE block that was obtained from the Norris Cancer Hospital and Research Institute at the University of Southern California Keck School of Medicine (USC). This tissue block was processed routinely (formalin-fixed 24h and processed by automatic equipment). 

Stein H, Gatter K, Asbahr H, et al. Use of freeze-dried paraffin-embedded sections for immunohistologic staining with monoclonal antibodies. Lab. Invest. 1985 52 676-683. 

Roos N. Freeze-substitution and other low temperature embedding methods, in Electron Microscopy in Biology—A Practical Approach (Harris JR, ed.), IRL Press, Oxford, UK, 1991, pp. 39-58. 

Czymmek KJ, Bourett TM, Howard RJ. Immunolocalisation of tubulin and actin in thick-sectioned fungal hyphae after freeze-substitution fixation and methacrylate de-embedment. JMicrosc 1996 181 153-161. 

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. 

C. These freeze-dried sections were dry mounted on microscope slides which had been precoated with either Kodak NTB-3 or NTB-10 emulsion. Other techniques which thawed the frozen section, embedded the tissue in paraffin or dipped the section in liquid emulsion were demonstrated to translocate diffusible compounds. Many other similar attempts have been and are currently being made to localize diffusible compounds by autoradiography at the electron microscope level. 

Immerse the tissue blocks in an embedding medium, and freeze quickly with crushed dry ice. The frozen tissue blocks can now be stored at —80°C. 

Immerse the chuck with the tissue slice into the freezing solution. Freezing is indicated by a change in color of the embedding solution from clear to white and will be completed in 5-10 s. After 10 s, remove the chuck and tissue from the freezing solution, and place them on dry ice (see Note 5). 

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). 

Air-entraining admixtures, therefore, produce concrete which is more durable to conditions of freezing and thawing, particularly in the presence of de-icing salts, more resistance to sulphate attack, provides better protection to embedded reinforcement and is more tolerant of poor curing conditions. There appears to be no... 

Proteins can be detected in tissue sections or cell cultures using similar immune detection systems. Use of an antibody to detect specific proteins in tissues is called immunohistochemistry, whereas detection of proteins in cell suspensions is called immunocyto-chemistry. Tissues can be prepared by fixation and embedding in paraffin wax, or by rapid freezing in a compound that inhibits ice formation in the tissue, so as to preserve cell morphology. Some antibodies do not work well with paraffin-embedded tissues, probably because the antibody cannot access the antigen properly (133). The most common labeling system used for detection of the bound antibody is an enzyme-coupled secondary antibody that produces a color reaction... 

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