The adherent culture of human osteosarcoma epithelial cells (U2OS line) featured in the image above was transfected with a Cerulean FP-mitochondria subcellular localization vector, thus localizing a cyan fluorescent protein tag to the mitochondrial network. Images were recorded in grayscale with a 12-bit digital camera coupled to a Nikon TE-2000 inverted microscope equipped with a bandpass emission fluorescence filter optical block. During the processing stage, the Cerulean fluorescent protein channel was pseudocolored cyan. A separate channel was recorded using differential interference contrast and overlaid on the fluorescence channel to identify cell boundaries and common structural features, such as the nucleus.