ABSTRACT
This chapter details the applications of ultrastructural immunostaining to lung. Immunostaining offers an advantage over biochemical analysis in allowing the interpretation of the biological significance of a tissue component in terms of the specialized function at the site where it occurs. Pre-embedment immunostaining begins with fixation, and final results depend critically on this step. Keeping the fixation as brief as possible is to be recommended for achieving satisfactory sectioning and preserving cell surface constituents. Immunostaining of finely minced, fixed tissue blocks provides an alternative to staining sections. In these miniblocks, only a thin layer at the surface will stain. Intensification of electron opacity at a reactive site could prove advantageous for localizing antigens present in the section at low concentration or low level of immunoreactivity. Freeze-drying and embedding potentially eliminates all noxious influences on the antigen except those of the embedding medium and minimizes displacement of diffusable substances.
