Visualization and Quantification of Endogenous Intra-Organelle Protein Interactions at ER-Mitochondria Contact Sites by Proximity Ligation Assays

The need for new approaches to study membrane contact sites (MCSs) has grown due to increasing interest in studying these cellular structures and their components. Here, we present a protocol that integrates previously available microscopy technologies to identify and quantify intra-organelle and inter-organelle protein complexes that reside at MCSs.