HeLa cells. Immunofluorescent light micrograph of HeLa cancer culture cells. Their nuclei are orange, while the microtubules of their cyto- skeletons are green. At centre is a dividing cell. HeLa cells were established in 1952 as the first human cell line to research cancer. The cells were named after Henrietta Lacks, from whose cervix they were obtained. HeLa cancer cells are used worldwide as they grow unusually well in the laboratory. In immunofluorescence, antibodies are used to attach fluorescent dyes to specific cell tissues. In this case the nuclei have been stained with propidium iodide and the microtubules with anti-tubulin antibody. Magnification unknown.