The nucleolus is the largest structure in the nucleus of eukaryotic cells, where it primarily serves as the site of ribosome synthesis and assembly. Nucleoli also have other important functions like assembly of signal recognition particles and playing a role in the cell's response to stress. Nucleoli are made of proteins and RNA and form around specific chromosomal regions. [Wiki]

Store the Nucleoli Marker antibody at 2-8°C (with azide) or aliquot and store at -20°C or colder (without azide).