Localization of (QD564)-His6Cyclin E in live pre-MBT (4 hpf, 64-cell embryo, a-c) and MBT (6 hpf, 2048-cell embryo, d-f) Xenopus laevis embryos. One cell of embryos at the 2-cell stage was microinjected with (QD564)-His6Cyclin E and visualized using confocal microscopy. (a, d) fluorescence channel; (b, e) light channel; (c, f) merged fluorescence and light channels. Nuclei are marked with white arrowheads in panels b, f. Embryos were viewed with a 10X objective on a Zeiss LSM 510 confocal microscope equipped with a META detector, and analyzed using LSM510 Image Acquisition software. Scale bars are 100 μM. At least 20 embryos were injected and viewed in at least 3 separate experiments.