Membraneless organelles and liquid-liquid phase separation – methods for their characterisation

Membraneless organelles (MLOs) are a large group of intracellular compartments formed during various stages of a cell life. They are important subcellular structures which enable a cell performance of vital physiological processes including stress response. MLOs can be found in cytoplasm and organelles that are sealed by lipidic membrane, mainly in nucleus. They are formed by the thermodynamically driven liquid-liquid phase separation (LLPS). MLOs contain proteins possessing intrinsically disordered regions (IDRs) which together with RNA spontaneously phase separate from the surrounding milieu. This paper presents information on the biophysical basses of the formation and functionality of MLOs. It also discusses a range of experimental techniques that can be applied in biochemical and biological studies of these sub-cellular structures.