Interpreting the results of freeze-etching

Morphological data obtained by freeze-fracturing and other low temperature techniques must be interpreted in terms of molecular organization and function. Interpretation is aided by physical and biochemical approaches. Physical approaches such as rotary replication and ultralow temperature fracturing can improve resolution and preserve molecular arrangements which are difficult or impossible to observe with standard freeze-etching techniques. Biochemical approaches such as dissociation-reconstitution experiments can establish the molecular parameters underlying electron-microscopically visible forms. Both approaches are illustrated by investigations of the human erythrocyte membrane.