Quantitative analysis of EdU incorporation on rice root meristems using EdU assay. Rice roots (O. sativa L. ssp. japonica 'Nipponbare') were incubated for 2, 4, 6 hours with 20 μM EdU which was detected using Alexa Fluor 488 azide (green). (A) Fluorescence stereo microscopy images of EdU-labeled root tips. Transmission images of roots were pseudocolored red and merged with green EdU signal. Scalebar 300 μm. (B) Laser scanning confocal microscopy images of single optical sections of 6 μm (optical depth) on the median plane of rice root tips. Cell wall autofluorescence (red pseudocolor) and transmission images were overlaid onto green EdU signal. Inset photo shows a close-up of a 4 h EdU-treated cell with EdU-Alexa Fluor 488 labeled segregating chromosomes. Scalebar 300 μm. (C) Confocal images of EdU-labeled and DAPI-stained (DNA) cells from the meristem region of 2 h EdU treated root tips. Arrowheads (from left to right) indicate an anaphase, a prophase and a metaphase cell with well-preserved morphology. Scalebar 10 μm. (D) Quantitation of average EdU signal intensity of the meristem region after 2, 4 and 6 hours EdU incubation.