Advanced imaging of membrane contact sites

Organelle membrane contact sites (MCSs) coordinate key cell activities and their alterations are associated with several high-incidence disorders, prompting an increasing interest in their study. However, the investigation of MCSs is challenging, mostly because of their nanometric size and dynamic nature. Here we highlight the methods that are available for analysing MCSs. We focus on advanced imaging techniques and discuss their advantages and limitations, providing practical guidance for researchers approaching this field. We propose to study MCSs through a combination of different methodologies, complementing their visualization with investigation of the associated functions. To this end, we also discuss the need to develop innovative biosensors.