Mitotic PtK1 cell microinjected with X-rhodamine-labeled tubulin and Alexa 488-labeled CENP-F antibodies, to fluorescently label kinetochore fibers (red) and kinetochores/spindle poles (green), respectively.

This cell possesses a merotelically oriented kinetochore (top right kinetochore) that is connected to the upper pole by a thick microtubule bundle and to the lower pole by a thin microtubule bundle.
As the cell enters anaphase, the merotelic kinetochore moves toward the upper pole without loosing connection to the opposite pole.

Digital images were acquired every 20-60 seconds at a 60X magnification. Elapsed time is shown in min:sec