ABSTRACT
This chapter describes the recently developed lectin methods for characterizing glycoconjugates in situ placing emphasis on technical details and application to the study of normal and pathologically altered respiratory tract. As the initial step in tissue processing, fixation is the single most important element in determining the outcome of histochemical reactions. A method of processing tissues involves rapid freezing of small blocks of fixed or unfixed tissues and sectioning in a cryostat. Cryosections of unfixed tissue are normally fixed briefly prior to histochemical staining. The earlier light microscopic techniques of carbohydrate histochemistry were based on the selective reactivity of functional groups found in complex carbohydrates, such as vicinal diols, sulfate esters, and so on. Postembedment techniques for demonstrating complex carbohydrates are evolving rapidly. This approach offers an important advantage in avoiding the severe limitations imposed on pre-embedment methods from failure of the reagent to penetrate the tissue, the cell, or the organelle.
