Reinforcement and protection with polystyrene of freeze‐fracture replicas during thawing and digestion of tissue

Abstract
An improved method for reinforcing freeze-fracture replicas, which is especially suitable for tough tissues, is described. For this purpose, polystyrene dissolved in chloroform is used to produce a solid protecting layer of plastic on top of the replica, enabling it to withstand the stresses associated with the thawing and digestion of the tissue with strong acids. The method results in production of large replicas from tissues such as skin or peripheral nerve [from humans] which are difficult to process. The method can also be used profitably for reinforcing other softer and more homogeneous tissues.