A theoretical and technical study of autography as a histological method for localization of radioactive elements

An "autograph", also known as a "radioautograph", "autoradiography or "historadiograph", is the "signature" left by a radioactive particle in a photographic emulsion, and is, therefore, the visual evidence of the presence of radioactivity in the structure in contact with the photographic emulsion. Radioisotopes present in biological material may be detected in two ways: 1) chemically, using the Geiger counter method and 2) histologically, using the above photographic technique - autography. It is the latter technique, however, that not only reveals the presence of the radioisotope within the specimen but also allows the isotope to be traced to its precise site in the tissue structure