Mitosis. Immunofluorescent light micrograph of HeLa cancer cells, one of which (centre) is in the prophase stage of mitotic cell division. The chromosomes (blue) have condensed before dividing to form two nuclei. In mitosis, two genetically identical daughter cells are formed. The cells are stained to reveal actin microfilaments (green) and microtubules (red) of the cytoskeleton. Round nuclei are blue. HeLa cells, cancerous cells used in cancer research, were named after Henrietta Lacks, from whose cervix they were obtained. Immunofluorescence uses antibodies to attach fluorescent dyes to specific cell tissues. Magnification: x500 at 35mm size.