Characterization of drug treatment effects on cellular and subcellular morphology in late G2. (A) Timeline for cell cycle synchronization using a double thymidine block followed by drug treatment. HeLa cells were used; at the time of fixation, most cells had reached late G2, just before entering mitosis. (B) Representative images of HeLa cells in late G2 fixed and stained after drug treatment. Cropped images of representative cells from each experimental condition are shown. Scale bar, 20 µm. (C) Correlation matrix for all features used in the cell phenotype profiling shown in Fig. 2 B. See Table S1 for detailed descriptions of each feature. (D) UMAP plots of cell phenotype profiles. The UMAP data from Fig. 2 B are shown, with each condition highlighted individually for clarity. (E) Selected features that robustly reflect the effect of drug treatment on Golgi morphology in late G2. Drug names associated with a strong effect on each feature are underlined in color. Features include dist_nuc_Golgi (distance between the centers of mass of the nucleus and Golgi) for SP, peaks_num_Golgi and peaks_xy_std_Golgi (number and spatial variance of GM130/Golgi fluorescence peaks) for taxol, and area_Golgi and mean_Golgi (area and mean fluorescence intensity of the GM130/Golgi region) for BFA and CytD. Full data are provided in dataset 3. (F) Notable features in addition to those related to Golgi morphology. These include cv_ki67 (CV for nuclear Ki-67 fluorescence intensity, i.e., SD normalized by the mean) for SP and mask_area (cell mask area) and cv_actin (CV of phalloidin/actin staining) for CytD. Full data are provided in dataset 3.