Real-Time Imaging of Nanoscopic Lipid Domains using iSCAT

Cell membranes segregate their components into nanoscopic rafts. The small (10-100 nm) and transient (< 100 ms) nature of these domains have made them difficult to study. We use interferometric scattering microscopy (iSCAT) to perform label-free imaging of lipid domains with sub-millisecond time-resolution and nanometre accuracy. Heating of individual domains reduces their size below the diffraction limit and enables us to access a range of sizes; these nanoscopic lipid domains are within our detection limit. We estimate a minimum resolvable domain size of 40 nm for the achievable contrast in this preliminary work.