New DNA-based Localisation Microscopy Approaches to Study Protein-Protein Interactions and Nanoscale Protein Placement in Situ

It is crucial to visualize biomolecules and their molecular-interaction complexes directly within cells, to show precisely where these interactions occur and thus improve our understanding of cellular regulation. In this presentation I will present new approaches to image proteins and protein-protein interactions that are based on synthetic DNA interactions and allow localisation with ~10 nm precision. Two schemes will be presented, called PD-PAINT (proximity-dependent PAINT) and Repeat DNA-PAINT which are improvements of the localisation microscopy technique called DNA-PAINT. I will describe the basis of these approaches and demonstrate their application to biophysical questions in cardiac biophysics. We show that these schemes can be straightforwardly integrated in a multiplexed super-resolution imaging protocol and benefit from advantages of DNA-based super-resolution localization microscopy, such as high specificity, high resolution and the ability to image quantitatively.