1. General

1.1 General presentation

In autoradiography, a photographic emulsion replaces the counter normally used to measure radioactivity. Counting techniques based on the principle of ionization or excitation provide rapid information on the activity of the source expressed in Bq/mg of tissue, without providing information on where the radioactivity is distributed in the tissue. Autoradiography can record the distribution of radioactivity in tissue with great precision because each silver halide crystal in the photographic emulsion is an independent detector isolated from the rest of the emulsion by its gelatin envelope. This specificity cannot be achieved with counters, unless tissue fractions are isolated with great precision, which is extremely difficult at the cellular or even sub-cellular...