Optimization of stereoscopic and high angle tilting procedures for biological thin sections

Abstract

SUMMARY The use of stereoscopic and high angle tilting facilities in electron microscopes to optimize information retrieval from thin sections of biological material is reviewed. Some of the technical problems involved are analysed in detail and problems of interpretation of stereo‐pairs and the necessity of ‘learning to see depth’ in such unfamiliar visual situations is emphasized. A table suggesting methods of optimizing various parameters is presented. An indication of some of the unanticipated results which have arisen from the work and of the consequent reservations about currently accepted routine evaluations of biological sections, especially as regards their thickness, are considered. The validity of serial section reconstruction at the 10–50 nm level needs careful consideration.