Preparing Hydra for Freeze-Fracture and Freeze-Etching

  • Richard L. Wood


The freeze-fracture technique is particularly advantageous for the study of cell surfaces and intercellular junctions. In general, it involves the rapid freezing of tissues, either with or without partial sublimation of ice (etching). By evaporating a film of pure carbon on the exposed surface, a replica of the cell surface is obtained which reveals its intimate contours. Contrast is obtained by shadowing the exposed surface with evaporated platinum prior to forming the replica. The tissue is removed from the replica by digestion in caustic solutions prior to recovery of the replicas for viewing at the electron microscope (Koehler, 1972). When a fracture occurs along the plane of a biological membrane it tends to split the lipid core and reveal unique surfaces for subsequent replication (Branton, 1966). Junctional regions can be identified by the arrangement of intramembranous particles, which appear to consist predominantly of protein. The distribution of surface components can be localized by combining the freeze-etching procedure with surface probes conjugated with large molecular weight compounds such as ferrittn.


Exposed Surface Sodium Cacodylate Lipid Core Rapid Freezing Caustic Solution 
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Copyright information

© Springer Science+Business Media New York 1983

Authors and Affiliations

  • Richard L. Wood
    • 1
  1. 1.Department of AnatomyUniversity of Southern California, School of MedicineLos AngelesUSA

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