ABSTRACT
This chapter gives a further selection of methods, as alternatives to the thin sectioning. Specimens other than sliced tissue are found as free cells or disaggregated tissue, or else as entire organisms which may be mounted in dry or fluid form. Cytological examination can be made of cells exfoliated into body fluids. Cytological specimens are collected unfixed, and therefore must be treated as potentially infectious. The most usual fixatives are the alcohols ethanol and methanol. The cell block also occupies an intermediate position between cytology and histology. Squashing is used for material that is just too hard for smearing, but cannot be sectioned without embedding. Temporary mounts are useful for quick examination, for example to check a sample in the course of collection or permanent preparation. Gum media tend not to lend themselves well to deep cells nor indeed to many small Protozoa or invertebrates, whose refractive indices equate with the mounting medium with time, causing the object to Vanish’.
