Immunofluorescence with mouse anti-alpha-tubulin was employed to visualize the details of the microtubule network in the log phase monolayer culture of human osteosarcoma cells presented above. The secondary antibody (goat anti-mouse IgG) was conjugated to Alexa Fluor 488. In addition, mitochondria in the cells were targeted with MitoTracker Red CMXRos, a derivative of X-rosamine. Images were recorded with a 60x oil immersion objective using a zoom factor of 4.0 and sequential scanning with the 488-nanometer spectral line of an argon-ion laser and the 543-nanometer line from a green helium-neon laser. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.