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FIXATION OF FISH TISSUES. IN: THE LABORATORY FISH.
Citation:
Fournie, J W., R. M. Krol, AND W. E. Hawkins. FIXATION OF FISH TISSUES. IN: THE LABORATORY FISH. 2000, Chapter 34, Gary Ostrander (ed.), Handbook of Experimental Animals: The Laboratory Fish. Academic Press, New York, NY, , 569-578, (2000).
Impact/Purpose:
Chapter providing information dealing with the principal of fixing fish tissues.
Description:
This chapter deals with the fixation of fish tissues and whole fish. Traditionally, fixation has been applied to animal tissues mainly for histological or pathological studies. Development of new molecular and immunologic tools now allows tissue and cellular localization of nucleotide sequences and antigens, even from archived specimens. With fishes, the need for conducting anatomical pathology analyses has increased in recent years due to the incorporation of fish health condition as a component in state and federal monitoring programs, the need to monitor the health of various types of finfish in aquaculture and the increased use of fish models in aquatic toxicology, carcinogenicity testing, and biomedical research. Molecular and immunologic applications involving fish have lagged behind those using mammals but, for the most part, reagents and procedures used for mammals are directly applicable to fishes. Regardless of application, specimens must be properly processed so that structure is maintained and reliable histological evaluations can be performed. The process begins with fixation, the most important step in producing good histologic specimens. Realizing that no one fixative is ideal for all situations, careful consideration should be given to study objectives and to potential future uses of the specimens. In this chapter, we provide information dealing with the principal of fixing fish tissues beginning with a brief discussion of the purpose of fixation and the basic elements of the chemistry of fixation. We describe the various types of fixatives available, provide recipes for the most commonly used fixative mixtures, and briefly discuss the advantages and disadvantages of the fixatives. The choice of fixatives for specific procedures such as preparation of liver tissue for light microscopy, the preparation of whole small fish for histological evaluation, and the use of molecular and immunohistochemical techniques are discussed. As modern communication technologies increase the speed of exchange and availability of information, the Internet becomes more important. Here, we list and briefly describe some currently accessible websites and servers that might be useful when considering studies that deal with fixation of fish tissues. Fixation protocols for fish in general are found in Hinton (1990). Protocols for several individual species include the following: channel catfish Ictalurus punctatus (Grizzle and Rogers, 1976), striped bass Morone saxatilis (Groman, 1982), several salmonids (Yasutake and Wales, 1983), and guppy Poecilia reticulata and Japanese medaka Oryzias latipes (Fournie et al., 1996).