Cellules en cours de division lors de la métaphase
Abnormal metaphase HeLa cell metaphase (i.e. the second phase in the mitotic cell-division sequence), observed using fluorescence microscopy. The DNA is marked in blue. Tubulin (hence the mitotic spindle, partly concealed by blue chromosomes) is shown in green. The metaphase is abnormal, due to the presence of three centromeres with mitotic spindles, rather than two (in green). Here, scientists are analysing this stage of mitosis as part of a study into a particular type of cell-death: mitotic catastrophe. This phenomenon is caused either by a defect in the cell cycle sequence or by a DNA alteration.