Answer:
In electron micrograph images of mitosis, structures are typically not stained fluorescent blue, as electron microscopy uses electrons rather than light, and does not involve the use of fluorescent dyes.
However, if we consider fluorescence microscopy images of mitosis, which use fluorescent dyes to visualize specific cellular structures, the structures that are stained fluorescent blue will depend on the specific dyes used.
In general, dyes that stain DNA, such as DAPI (4',6-diamidino-2-phenylindole), Hoechst, or SYTOX, will stain the chromatin in the nucleus of the cell blue. During mitosis, the chromatin condenses into distinct chromosomes, which can be visualized as blue structures in fluorescence microscopy images.
It's important to note that the specific structures stained fluorescent blue may vary depending on the experimental setup and the specific dyes used.