One approach to visualize internal structures of the testis is histological sectioning of the material. The use of testicular samples allows a detailed analysis of the structure of both seminiferous tubules and the interstitial space. It is worth noting that key role in the control of germ cell development is assigned to Sertoli cells. Thus, in this chapter the special reference is made on visualization of Sertoli cells in the seminiferous epithelium in which they create a specialized microenvironment to support the germ cell development through the formation of the blood-testis barrier (BTB). The use of transmission electron microscopy (TEM) allows a deeper insight into the BTB morphology, especially the organization of the basal ectoplasmic specialization (ES) and coexisting intercellular junctions.Equally important, immunohistochemistry (IHC) is an appropriate technique to detect the localization of various proteins in paraffin-embedded and fixed tissues, i.e. testicular samples. A proper fixation allows to stabilize structure of the seminiferous tubules and preserve cells against irreversible damage. As such localization of various junction proteins connecting adjoined Sertoli cells and present in germ cell-Sertoli cell interfaces is possible. Also immunofluorescence (IF) is helpful to detect the distribution and relative abundance of the junctional proteins, while immunocytochemistry (ICC) is a valuable technique to show a protein distribution within a single cell (e.g. in Sertoli cell culture).
Keywords: Blood–testis barrier; Histology; Immunocytochemistry; Immunohistochemistry; Intercellular junctions; Sertoli cell; Testis; Ultrastructure.