FIG. 3.

GFP-bac infection of Pk1 cells does not require a mitotic event. Pk1 cells (2 × 10⁴/cm²) were seeded in the presence of aphidicolin on a coated 23-mm-diameter coverglass in a culture chamber mounted on an inverted fluorescence microscope connected to a video recorder and a digital still recorder. The cells were infected with GFP-bac at an MOI of 100. Mitotic events were scored by analysis of a continuous time-lapse video recording, as described in Materials and Methods. At 90-min intervals phase-contrast fluorescence images were captured to detect GFP expression, i.e., at 1.5 h (A), 6 h (B), and 12 h (C) after infection. Arrows indicate cells that have gone through mitosis; all other cells did not go through mitosis as determined by analysis of the video recordings.