Microscopy methods for morpho-functional characterisation of marine invertebrate haemocytes

In this chapter, a useful list of well-established morphological and functional protocols is provided, to facilitate the design of experiments in the field of the characterisation of haemocytes of marine invertebrates, which have been emerging in the last decade as model organisms in ecotoxicology, comparative immunology, phylogenesis and evolution. This treatment offers a brief collection of methods and procedures for both light and electron microscopy, most of which were previously developed for vertebrates and therefore require modifications and adjustments. Many suggestions to solve common difficulties and errors are presented and clearly explained, covering haemocyte collection, cell culture, techniques of staining, and enzyme histochemistry and immunohistochemistry to obtain the best results.