a, Features used for generating the mitotic standard time model after alignment for HeLa Kyoto cells (left) and U2OS cells (right). Grey line, normalized feature value over time of individual cells; black line, mean. b, Mitotic standard time transitions for HeLa cells (left) and U2OS cells (right). c, Standard mitotic U2OS cell represented by the cell closest to the average of each mitotic standard stage. Each mitotic stage was assigned duration (coloured line), its duration s.d. (grey line) and a biological annotation.