Light micrograph of dividing HeLa cells. Chromosomes in the cell nucleus (purple), microtubules in the cell cytoskeleton (tubulin; green), and actin (red) are visible here. In the cell in the centre of the image, condensed chromosomes (purple) have aligned and attached to the spindle (green). During anaphase (one of the stages of nuclear division in mitosis), the spindle pulls the condensed chromosomes to opposite poles of the cell. The cell will finish dividing its nuclear material and then cytoplasm in order to physically separate into two daughter cells.
HeLa cells are an immortal human epithelial cell line derived from a cancerous tumour of the cervix (adenocarcinoma). It was established in 1951 from a biopsy taken from Henrietta Lacks and was the first human cell line to survive and grow in the laboratory. Henrietta's cells were originally used in this way without permission from her or her family which raises issues about ethics and privacy. HeLa cells have been used extensively around the world in many different fields of research including cancer research, immunology and vaccine development. Width of image is 100 micrometres.