Intracellular membraneless organelles and their myriad cellular functions have garnered tremendous recent interest. It is becoming well accepted that they form via liquid–liquid phase separation (LLPS) of protein mixtures (often including RNA), where the organelles correspond to a protein-rich droplet phase coexisting with a protein-poor bulk phase. The major protein components contain disordered regions and often also RNA-binding domains, and the disordered fragments on their own easily undergo LLPS. By contrast, LLPS for structured proteins has been observed infrequently. The contrasting phase behaviors can be explained by modeling disordered and structured proteins, respectively, as polymers and colloids. These physical models also provide a better understanding of the regulation of droplet formation by cellular signals and its dysregulation leading to diseases.

细胞内无膜细胞器及其无数的细胞功能最近引起了极大的兴趣。它们是通过蛋白质混合物（通常包括RNA）的液相-液相分离（LLPS）形成的，这种细胞器对应于富含蛋白质的液滴相与缺乏蛋白质的本体相共存，已被人们广泛接受。主要蛋白质成分包含无序区域，通常还包含RNA结合结构域，无序片段本身很容易经历LLPS。相比之下，很少观察到结构蛋白的LLPS。可以通过将无序和结构化蛋白质分别建模为聚合物和胶体来解释相反的相行为。