A monolayer culture of fox lung cells (shown above) was treated with MitoTracker Red CMXRos in medium containing 15 percent Cosmic calf serum, fixed with the same medium containing 3.7 percent paraformaldehyde, and permeabilized with 0.2 percent Triton X-100. The cells were then labeled for the filamentous actin network with Alexa Fluor 488 (pseudocolored blue) conjugated to phalloidin and counterstained with TO-PRO-3 (pseudocolored green), targeting DNA in the nucleus. 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.