Abstract
To investigate the chromosome dynamics during mitosis, it is convenient to mark the discrete chromosome foci and then analyze their spatial rearrangements during prophase condensation and telophase decondensation. To label the chromosome regions in plant chromosomes, we incorporated the synthetic nucleotide, 5-ethynyl-2'-deoxyuridine (EdU), which can be detected by click-chemistry, into chromatin during replication. Here, we described a protocol of a method based on the application of semi-thin sections of Nigella damascena L. roots embedded in LR White acrylic resin. The thickness of semi-thin (100-250 nm) sections is significantly lower than that of optical sections even if a confocal microscope was used. This approach may also be suitable for work with any tissue fragments or large cells (oocytes, cells with polytene chromosomes, etc.).