ABSTRACT
Monoclonal antibodies for studying the tissue localization of antigens are best isolated using immunocytochemical screening against fixed tissue. The objective in immunocytochemical staining is to choose conditions that optimize antibody-antigen binding and that allow the best possible tissue preservation while at the same time making the tissue penetrable to macromolecular antibodies. To obtain optimal intensity, immunocytochemical staining for a particular monoclonal antibody may require experimenting with different types of fixation, different ways of making the tissue penetrable to antibodies, and even different kinds of second antibodies conjugated to fluorescent tags or enzymes. To confirm that a monoclonal antibody or an antiserum specifically reacts with a certain antigen, the antibodies are blocked through incubation with the antigen prior to immunocytochemical staining. Immunocytochemical staining with monoclonal antibodies present different background problems than staining with polyclonal antisera. Different fixations may differentiate between different antigens to which a given monoclonal antibody binds.
