Freeze-substitution of Drosophila heads for subsequent [3H]2-deoxyglucose autoradiography

High resolution of [3H]2-deoxyglucose labelling was obtained in autoradiographs of Drosophila brains after freeze-substitution in anhydrous acetone at -76 degrees C. This method was applied to preparations which received visual, olfactory and mechanosensory stimulation. The autoradiographs were compared to those obtained after freeze-drying. Freeze-substitution, which has proved to be technically simple, rapid and inexpensive, yields a good quality of tissue preservation and hence is recommended for tissue dehydration prior to autoradiography.