PREPARATION OF TISSUES FOR LOCALIZATION OF SEX HORMONES BY AUTORADIOGRAPHY .3. A CRITICAL EVALUATION OF METHOD USING FREEZE DRYING, OSMIUM TETROXIDE VAPOUR FIXATION AND EPON EMBEDDING

The intracellular localization of 3H-oestradiol in various tissues was examined. For this purpose standard autoradiograms were prepared after freeze drying, osmium vapour fixation and Epon embedding. The radioactive material showed a preferential localization in all the tissues studied, viz. uterus, vagina and anterior pituitary gland. In all tissues a major proportion of the radioactivity was associated with the cell nuclei. Radioactive labelling outside the cell boundaries and in the surrounding connective tissue was almost lacking. Likewise, a very low number of silver grains were found over the Epon in the clefts and at the margin of the tissue sections. The observations appear to indicate that the diffusion and probably also the intracellular dislocation of the radioactive material are very limited. The validity of the results was examined. Pre- and postmortem changes, rapid freezing and osmium vapour fixation were not observed to influence the localization of the radioactivity. Furthermore, the localization was the same whether embedding was carried out at -10°C or at 50°C. It is concluded that freeze drying, osmium vapour fixation and Epon embedding provide a valid method for accurate intracellular localization of steroid sex hormones. © 1969 Springer-Verlag.