Methacrylate sections

From large pieces of tissue, paraffin sections of fixed tissue or cryostat sections of fresh or fixed tissues are prepared (Table 11.3). Many laboratories prefer either one or the other. Cryosectioning is rapid and relatively easy but morphology may be better preserved with paraffin sectioning. Methacrylate sections are used rarely for ISH. The sensitivity of ISH on paraffin-embedded tissue sections or on cryosections has rarely been compared (Lum, 1986 Tournier et al., 1987) but does not seem to differ greatly. This may depend on the type of tissue and the nature of the target nucleic acid. 

For more detailed histological studies, organs can be cut by a scalpel blade into small parts, which are then dehydrated in alcohol and embedded either in paraffin wax or glycol methacrylate. Wax sections are counterstained in 0.1% nuclear fast red. Methacrylate sections are counterstained in 0.1% cresyl violet in 1% acetic acid (pH 3.3) for 50min at 40°C. 

Fig. 5S. Apical part of a serous bronchiolar epithelial cell of an unmedicated female white rat (breeder Winkehnann, Borchen-Kirchhorchen) fixed on January 15, 1968 under me-thitural anaesthesia hy intratracheal instillation of 2.5 % glu-taraldehyde in phosphate buffer (pH 7.4) before opening the thorax. Postfixation with 1 % osmium tetroxide in phosphate buffer (pH 7.4). Contrasted en bloc with 0.5 % uranyl acetate in 70 % ethanol. Embedded in a 2 mixture of methyl and butyl methacrylate. Sectioned at 50 nm. Lead citrate after Reynolds (1963). Film 203/84...

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