Figure 4. Cyclin B1 and securin are not degraded during decoupled mitotic exit. (A) Quantitative immunofluorescence was performed on HeLa cells treated as in Figure 3A and stained with DAPI (DNA, gray), and antibodies against cyclin B1 and securin. A Fire LUT was applied using ImageJ to the original raw unaltered images to clearly show the levels of staining for each protein. Scale bar = 10 µm. (B) The intensity of staining for each antibody (cyclin B1 and securin) was measured in each unaltered cell, normalized to interphase levels, expressed as fold increase and displayed as box-plots with 5 to 95% confidence intervals. The total number (n) of cells counted for each group is indicated. (C) HeLa cells were synchronized with thymidine, released, and treated with RO at 6 h post-release. Samples were then harvested at the indicated times post-release, lysed, and analyzed by western blot with the indicated antibodies. All data shown are representative images from 3 independent experiments.