The HeLa cell culture shown in this confocal image was labeled with mouse anti-alpha-tubulin primary antibodies followed by goat anti-mouse secondary antibodies conjugated to Alexa Fluor 488. In addition, the specimen was stained with Alexa Fluor 546 (pseudocolored blue) conjugated to phalloidin and TO-PRO-3, targeting the filamentous actin network and cell nuclei, respectively. Images were recorded with a 60x oil immersion objective using a zoom factor of 2.5 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.