ABSTRACT
This chapter presents some technical aspects of immunochemistry and analyses the application of methods in fish gill research. The components of secondary active chloride secretion identified using electrophysiological and pharmacological techniques have all been identified and localized by immunochemistry. There are a number of reviews that address the role of branchial ion transport proteins in fish ionoregulation. Immunocytochemistry has become almost a standard technique to study the branchial mitochondria-rich ‘chloride’ cell. Research of fish gill ion transporters has, however, relied on the use of nonhomologous mammalian antibodies largely due to their availability and species cross-reactivity. Fixation serves to preserve the structural integrity of the tissue and to insure that cellular components remain in place. Good fixation generally comes at a cost to tissue antigenicity and a compromise must be made. Embedding of fixed tissue in paraffin or cryo-embedding for sectioning or whole mounting are commonly used.
