Radioautography (RAG) is a technique designed to show the pattern of the positioning of miscellaneous compounds labeled with radioactive isotopes (RI) in specimens. The physical techniques using RI-labeled compounds and the histochemical techniques are employed by RAG. Besides, the histochemical techniques deal with tissue sections via coating sections including RI-labeled precursors with photographic emulsions and disposing exposure. By using RAG, both the insoluble compounds tied to the macromolecules and the soluble compounds propagating in the cells and tissues can be demonstrated. In biological and medical research, the specimens of this technique are commonly cells and tissues containing radioactive substances, however, in natural sciences that are always plants, animals, and minerals.