Localization of the neuronal cell adhesion molecule D2-protein in explant cultures of dorsal root ganglia by use of the colloidal-gold immunocytochemical technique.

The localization of the neuronal cell adhesion molecule (N-CAM), D2-protein, in explant cultures of rat dorsal root ganglia was investigated at the electron microscope level by the use of 17-nm-diameter colloidal gold particles coated with swine anti-rabbit immunoglobulin molecules. The minimum amount of IgG needed to coat the gold particles and the pH optimal for coating were both determined. Immunocytochemical studies of cultures revealed the binding of gold particles to the neuronal plasma membrane, especially on neuritic processes. Schwann cells were not labeled, and the level of unspecific background staining was very low.