Chapter 3 Freeze-Fracture Deep-Etch Methods

Abstract

Publisher Summary Freeze-fracture deep-etch methods avoids the use of both chemical fixatives and cryoprotectants and results in the production of a three-dimensional replica of the etched surface of the specimen. Samples are ultra-rapidly frozen and fractured, the ice is sublimed under vacuum from the fracture surface, and the specimen is replicated. Using this technique, great advances have been made in the understanding of the structure and molecular make up of animal cell cytoplasm. The one main advantage of the rapid-freeze deep-etch technique is that little prior preparation of material is needed other than that required by the experiments that are being carried out. Therefore, most of the material requirements are in the instrumentation, and accessability to the necessary freezing and fracturing equipment is often the major limitation in the application of this technique. The procedure can be split into two separate events: freezing, followed by the fracturing, etching, and replication of the frozen material. Specimens can be frozen and stored under liquid nitrogen for any length of time prior to the fracturing procedure.