Immunocytochemistry (ICC) can be a very effective method for visualizing the localization and behavior of intracellular proteins, however the protocol for each ICC experiment should be optimized specifically to the cell being examined. Permeabilization, or the puncturing of the cell membrane, is an extremely important step in detecting intracellular antigens with a primary antibody because it allows entry through the cell membrane. Permeabilization is introduced after cells have been prepared with a fixative agent to initiate protein cross-linking, such as formaldehyde or ethanol.
