Resolving the spatial relationship between intracellular components by dual color super resolution optical fluctuations imaging (SOFI)

Background: Multi-color super-resolution (SR) imaging microscopy techniques can resolve ultrastructural relationships between- and provide co-localization information of- different proteins inside the cell or even within organelles at a higher resolution than afforded by conventional diffraction-limited imaging. While still very challenging, important SR colocalization results have been reported in recent years using STED, PALM and STORM techniques. Results: In this work, we demonstrate dual-color Super Resolution Optical Fluctuations Imaging (SOFI) using a standard far-field fluorescence microscope and different color blinking quantum dots. We define the spatial relationship between hDcp1a, a processing body (P-body, PB) protein, and the tubulin cytoskeletal network. Our finding could open up new perspectives on the role of the cytoskeleton in PB formation and assembly. Further insights into PB internal organization are also reported and discussed. Conclusions: Our results demonstrate the suitability and facile use of multi-color SOFI for the investigation of intracellular ultrastructures.