The proximity between the F-actin and mitochondrial networks was revealed in Mongolian gerbil lung cells by staining a GeLu culture with Alexa Fluor 488 conjugated to a phallotoxin (phalloidin) and MitoTracker Red CMXRos (pseudocolored yellow). The red-absorbing dye TO-PRO-3 was used to counterstain the cells for DNA in the nucleus. Images were recorded with a 60x oil immersion objective using a zoom factor of 2.0 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.