Abstract
Nucleolar isolation is a crucial technique for the study of nucleolar contents and regulation of ribosome biogenesis. Lysed cells are spun through various concentrations of sucrose and magnesium chloride to separate the notoriously dense nucleoli from the rest of the cell. Here we describe isolation of nucleoli from the breast cancer cell line MDA-MB-468. The resulting nucleolar fraction is subjected to immunoblotting to confirm the purity of the nucleolar fraction.