Hygromycin B is widely used in molecular biology as a selective agent in cell culture. It is particularly effective in selecting and maintaining eukaryotic cells that have been genetically modified to express resistance to this antibiotic. This makes it a valuable tool in the development of stable cell lines for research purposes, such as studying gene function and protein expression. Additionally, it is employed in the selection of transgenic organisms, including plants and animals, ensuring that only those with the desired genetic modifications survive. Its application extends to the field of microbiology, where it is used to select for bacteria containing specific plasmids with hygromycin resistance markers, facilitating cloning and genetic engineering experiments.