HeLa cells in culture, fluorescent light micrograph. HeLa cells are an immortal cell line derived from the cervical cancer of the patient Henrietta Lacks in the early 1950s. The cells are widely used in biological research. These cells have been tagged with fluorescent dyes: nuclei are purple, the protein actin is red and microtubules are green. Actin and the microtubules are important parts of the cells' cytoskeletons. The cytoskeleton is a supportive internal framework in a cell, which aids its movement and the transport of chemicals and organelles within the cell. Magnification: x120 when printed 10cm wide.