Comparison and Criticism of Autoradiographic Methods

It was repeatedly emphasized that autoradiography with tritium will be influenced to a high degree by absorption of tritium-β-radiation. That is why we assumed differences in the preparation of specimens to be responsible for different grain yields. — Sections and squashes of one and the same tissue and animal were used for stripping film autoradiography. — In squashes there are plenty cells with higher grain numbers than are in sections, but there are also comparatively more cells with 1 and 2 grains. The whole grain number distribution in squashes is rather broad and uncharacteristic compared with that of sections, whereas distributions derived from sections usually show two definite peaks: one in the vicinity of zero and one representing the mean incorporation rate. — The reasons of these differences and the advantages and disadvantages of the different preparations are discussed.