Human melanoma cell undergoing cell division. The chromosomes (blue) have separated and the two daughter cells have almost split apart - only a small bridge of cytoplasm remains. The green staining labels the endoplasmic reticulum and the red labels the mitochondria. The image was produced on a confocal microscope; the ER and mitochondria are from a single optical section but the chromosomes are a 3D reconstruction from a series of sections.