Ratio of EdU-labeled and mitotic cells as dual parameter proliferation analysis of 2d-old plant cultures. EdU-labeled S-phase cells (in addition to cells which were recently in S-phase) and mitotic cells were scored as frequencies for the indicated cultures using EdU assay (green) and DAPI labeling (red), respectively. EdU was used at 10 μM concentration for 2 h. Inset photo shows an EdU-labeled maize cell (green) next to a cell in telophase stage of mitosis (red). In two independent experiments, more than 500 cells were counted for each culture. Scalebar: 10 μm.