Immunogold probes for light microscopy

Light microscope immunocytochemistry was initiated by the classical work of Coons et al. (1,2), who developed the immunofluorescent technique for antigen localization. All other immunocytochemical techniques are based on the same philosophy, but use different microscopically dense markers. For instance, Avrameas and Uriel (3) and Nakane and Pierce (4) described the use of the enzyme peroxidase as a dense marker for immunocytochemistry, and this was later developed by Sternberger (5), who described the sensitive peroxidase-antiperoxidase techniques. The initial immunoenzyme techniques have been further expanded by the use of alkaline phosphatase as a marker (6, see also this vol., Chapter 10 ). These techniques, including the original immunofluorescent technique, are all routinely used for immunohistochemistry. Recently, the use of colloidal gold probes as immunocytochemical markers has been described for electron immunocytochemistry (7), and these are now proving to be of use at the light microscope level.