The proximity between glial fibrillary acidic protein and vimentin, both of which are members of the class III intermediate filament protein family, was visualized in the rat hypothalamus section illustrated above. Before being treated with a cocktail of rabbit anti-GFAP and mouse anti-vimentin primary antibodies, the specimen was fixed, permeabilized, and blocked with 10-percent normal goat serum. The primary targets were visualized with goat anti-rabbit and anti-mouse secondary antibodies conjugated to Alexa Fluor 568 and Alexa Fluor 488, respectively. In order to detect cell nuclei, the tissue section was counterstained with DRAQ5 (pseudocolored cyan). Images were recorded with a 40x oil immersion objective using a zoom factor of 1.6 and sequential scanning with the 488-nanometer spectral line of an argon-ion laser, the 543-nanometer line from a green helium-neon laser, and the 633-nanometer line of a red helium-neon laser. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles unless otherwise noted above.