Ultrafast particle tracking of single lipid molecules in membranes through ISCAT and MINFLUX microscopy
in: European Biophysics Journal with Biophysics Letters (2021)
The diffusion dynamics of lipids on cellular membranes have always proven particularly challenging to study in optical microscopy, given the highly heterogeneous nature of their environment. Given the breadth of the relevant spatiotemporal scales to detect such heterogeneities, very few optical techniques are able to probe these intervals with single molecule level of detail. Interferometric Scattering (ISCAT) microscopy, for example, can reach kilohertz sampling rates with high signal to noise ratios. We employed this technique to probe the diffusion of single lipids on cellular membranes. Using a novel analysis approach to the single particle trajectories thus collected, we were able to uncover new details pertaining to the compartmentalization of the cellular membrane at the nanoscale. The recently developed MINFLUX offers a new outlook on this problem, thanks to the simultaneous reliance on non-invasive synthetic fluorescent tags, and high signal to noise ratios obtained through minimal photon fluxes. We will also show preliminary data to demonstrate the potential of this new approach to the detection of single particle diffusion in biological samples.