The opossum kidney cells presented in the digital image above were resident in a culture that was immunofluorescently labeled with anti-tubulin mouse monoclonal primary antibodies followed by goat anti-mouse Fab fragments conjugated to Alexa Fluor 568 (pseudocolored green). F-actin in the cells was targeted with Alexa Fluor 488 conjugated to phalloidin (pseudocolored blue), and DNA was counterstained with DRAQ5. In the dividing cell in the center of the image, the DNA can be seen organized into sets of chromosomes, whereas the nucleic acid in the cell along the lower left-hand side is more diffuse, so that the entire nucleus appears red. Images were recorded with a 60x oil immersion objective using a zoom factor of 3.5 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.