Imaging of chromosomes in fixed cells provides only indirect information on chromosome dynamics. In addition, fixation of cells sometimes causes an artificial distortion of chromosome distribution. Hence, the complex dynamics of chromosomes during cell division can only be addressed through direct analysis of live cells. Two-dimensional time-lapse recordings of live cells have been widely used for the investigation of chromosome dynamics, and recent advances in z-stack projection techniques mean that we can now easily acquire a series of optical sections through the specimen. In particular, confocal microscopy and deconvolution methods have enabled high-speed and automated three-dimensional analyses [1].