Division of Radiooncology, Deutsches Krebsforschungszentrum, 69120 Heidelberg, Germany
Histological techniques have traditionally been important to detect and to analyse cellular compounds. The principle of histological staining relies on the treatment of tissue sections with dyes in solution which will react more or less specifically with defined cell and tissue structures. In the course of further developments of microscopical stainings, a significant step forward was obtained with the introduction of enzyme histochemistry. In the meantime, however, enzyme histochemistry in its strict sense has become a limited role. With the use of antibody labelings, originally introduced by AH COONS in 1941 as immunofluorescent technique, immunohistological methods are now regarded as tools with greater potential. This holds especially true with the introduction of new fluorochromes and the development of new types of microscopes.