Immunocytochemistry. See

Apart from the covalent bonding of an enzyme label, its attachment on the principle of immunochemical interaction has b n utilized in immunocytochemistry by Stemberger (see also 7.5). 

The table shows the sources of specimens, the type of preparation, and the fixation needed for immunocytochemistry Almost any type of specimen preparation or fixative can be used. The gentlest fixation is air-dried acetone, which consists of first air-drying the slide followed by a brief acetone postfixation (see Chapters 9-13)... 

Waxman While we are talking about concentrations of various molecules as they approach the node, years ago Landon and Langley showed that nodes of Ranvier in peripheral nerve are surrounded by a cuff of what they called gap substance . They subsequently presented some evidence that this acts as a cation binding lattice. There is also evidence that the gap substance can bind some anions. For those of you who do immunocytochemistry, this extracellular substance also binds many antibodies, so when you do immunocytochemistry on axons you not only see membrane fluorescence, but also artefactual or nonmembrane-associated binding of antibodies to this extracellular material surrounding the node. Gary Strichartz, do you want to comment on the issue of what concentrations of TTX, for example, are seen at a node of Ranvier, compared to those that you applied to a whole nerve ... 

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