A monolayer culture of A-10 myoblasts was treated with MitoTracker Red CMXRos in medium containing 15 percent Cosmic calf serum, fixed with the same medium containing 3.7 percent paraformaldehyde, permeabilized with 0.2 percent Triton X-100, and then counterstained with TO-PRO-3 (pseudocolored blue), targeting DNA in the nuclei. In addition, the filamentous actin network was labeled with Alexa Fluor 488 conjugated to phalloidin. 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.