Molecular crowding refers to the excluded volume restriction of the space available to molecules in a solution due to the high concentration of other molecules, particularly macromolecules like proteins and nucleic acids. This restriction of space, or excluded volume effect, leads to changes in the behavior and properties of the crowded molecules. In this chapter, we discuss how RNA affects crowding and is affected by it and describe techniques that allow us to study these phenomena. We also discuss methods to extract granules that can then be used to understand their components.