Mapping molecular assemblies with super resolution using ICY SODA colocalization analysis & new membrane probes (the MemBright family)
Elucidating molecular organization and protein functions requires localizing precisely single or aggregated molecules and analyzing their spatial distributions. We develop a statistical method SODA (Statistical Object Distance Analysis) that uses either micro- or nanoscopy to significantly improve standard co-localization techniques (Lagache et al, Nature Comm 2018). Our method considers cellular geometry and densities of molecules to provide statistical maps of isolated and associated (coupled) molecules. SODA can be used with three-color structured-illumination microscopy (SIM) images to statistically characterize spatial organization of thousands of protein clusters or vesicles. As this methods do not rely on physical overlaps, SODA can be used to detect indirect molecular association in conventional microscopy or even in super resolution microscopy where higher resolution prevent the use of conventional overlay methods.
To reconstitute molecular maps within cellular shape, we recently developed new membrane probes call the MemBright family (on the cover of Cell Chemical Biololgy, April 2019). MemBright is a family of six cyanine based fluorescent turn-on PM probes that emit from orange to near infrared when reaching the PM, and enable homogeneous and selective PM staining with excellent contrast in mono- and two-photon microscopy. These probes are compatible with long-term live-cell imaging and immunostaining both in cultures cells and tissue without any use of transfection or transgenic animals. MemBright probes can be used in super-resolution imaging to unravel the plasma membrane structures like the tiny dendritic spines protrusions. 3D multicolor dSTORM in combination with immunostaining can be used to labels receptors clustered at cell surface and to decipher molecular organization at single molecule level. This presentation will illustrate through various cell biology questions how MemBright probes constitute a universal toolkit for cell biology and neuroscience biomembrane imaging with a variety of microscopy techniques.
Institut de Psychiatrie et Neurosciences de Paris (IPNP)
Domain 4 - UMR 144 - Cell Biology and Cancer