Immunocytochemistry at the electron microscopic level has allowed the distribution of antigens in the cellular system to be examined. In transmission immunoelectron microscopy, two different approaches have been used, i. e., preembedding or
post-embedding methods, depending on whether labeling is carried out before or after the embedding process, respectively. The good preservation and expression of the antigenic molecules in the tissues are most important in the ultrastructural
immunocytochemistry. A low temperature resin, Lowicryl K4M for postembedding method is frequently used in many immunoelectron microscopic laboratories. Periodate-lysine-paraformaldehyde(PLP) fixed tissues are dehydrated and embedded at -20℃ in a
hydrophilic resin, Lowicryl K4M. The resin is easy to section and a good embedding material for preservation of antigenicity in the tissues. Immunogold labelling technique marks localization of antigenic molecules in the subcellular level.
In the scanning immunoelectron microscopy, a silver-enhancing technique can well express the antigenic immunogold particles using smaller gold probes(<15nm) in the standard scanning electron microscopy.
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