Freeze fracture techniques biological method

An alternative method is the freeze-etching technique [24, 25], which consists of producing platinum shadowed replicas of fractures created in rapidly frozen biological systems or lyotropic liquid crystals. The fracture orientation is somewhat haphazard, but occurs preferentially within the paraffinic level of the bilayers. These methods offer the possibility of viewing bilayers directly and preparing stereoviews. Beautiful pictures of liquid crystalline DNA, both cholesteric and hexagonal, have been obtained, but individual molecules are not easily resolved. However, the director distribution can be deduced from the images [26],... 

Important developments of the immunogold-based methods have also been derived ftom its combination with freeze-fracture in the study, e.g., of receptor [87] and gap-junction [88, 89] distribution. As we will discuss below, the combination with Golgi impregnation, pre-embedding HRP ICC and tracing, intracellular dye filling, enzyme methods, and molecular biology techniques has been very useful for correlative LM/EM analysis. 

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