A semi-confluent culture of owl monkey kidney cells (illustrated above) was fixed, permeabilized, and blocked with 10-percent normal goat serum in phosphate-buffered saline prior to immunofluorescent labeling with rabbit primary antibodies to GPP130, a protein resident in the Golgi complex of mammalian cells, and mouse primary antibodies to vimentin, an intermediate filament protein. The culture was subsequently stained with a mixture of anti-rabbit and anti-mouse secondary antibodies conjugated to Alexa Fluor 568 (pseudocolored yellow) and Alexa Fluor 488, respectively. In addition, the cells were treated with the nuclear counterstain TO-PRO-3. Images were recorded with a 60x oil immersion objective using a zoom factor of 3.0 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.