Until recently, it was thought that most of the important work in the cell goes on in organelles – specialized subunits enclosed by membranes. But Anthony Hyman and Clifford Brangwynne discovered an entirely new physical principle that concentrates cellular interactions between proteins and other biomolecules without the use of membranes.

They observed molecules, including RNA and proteins, rapidly forming dynamic, liquid-like droplets through a process called phase separation – much as oil droplets form in water. These droplets were able to drip, flow, fuse and split apart again, producing temporary structures, protected from the turmoil of the watery cell interior.

Since their discovery, they and others have shown that these membraneless liquid condensates play a role in numerous cellular processes, including signalling, cell division, the nested structure of nucleoli in the cell nucleus, and the regulation of DNA. Their discovery is a fundamental advance in our understanding of cellular organization, and is likely to lead to clinical applications in the future, potentially including neurodegenerative diseases such as ALS.