Lipid Expansion Microscopy

Abstract

Strategies to visualize cellular membranes with light microscopy are restricted by the diffraction limit of light, which far exceeds the dimensions of lipid bilayers. Here, we describe a method for super-resolution imaging of metabolically labeled phospholipids within cellular membranes. Guided by the principles of expansion microscopy, we develop an approach featuring cell-permeable reagents that enables direct chemical anchoring of bioorthogonally labeled phospholipids into a hydrogel network and is capable of tunable, isotropic expansion, thus facilitating super-resolution imaging of cellular membranes. We apply this method, termed lipid expansion microscopy, to visualize organelle membranes with precision, including a unique class of membrane-bound structures known as nuclear invaginations. As it is compatible with standard confocal microscopes, lipid expansion microscopy will be widely applicable for super-resolution imaging of phospholipids and cellular membranes in numerous physiological contexts.

Nanoscale fluorescence imaging of biological ultrastructure via molecular anchoring and physical expansion

“…4.4 ). The recently developed Lipid Expansion Microscopy (LExM) also combines metabolic labelling and click chemistry to achieve nanoscale imaging of the plasma and organelle membrane [ 63 ].…”