GPP130 is a transmembrane protein localized to the cis-Golgi. The culture of owl monkey kidney cells presented in the digital image above was immunofluorescently labeled with anti-GPP130 rabbit monoclonal primary antibodies followed by goat anti-rabbit Fab fragments conjugated to Alexa Fluor 488 (yielding green fluorescence). In addition, the specimen was stained for DNA in the nucleus with the red-absorbing dye TO-PRO-3. Images were recorded with a 60x oil immersion objective using a zoom factor of 4.5 and sequential scanning with the 488-nanometer spectral line of an argon-ion 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.