New Multimodal Probes for Correlative Light-Electron Microscopy
Hussein Ftouni, Frederic Bolze, Jean-Francois Nicoud, Yannick Schwab, Jean-Luc Rehspringer, Rodrigues R. Mafouana and Youri Arntz
Two-photon Excited Microscopy (TPEM) and Electron Microscopy (EM) became in the past few years routine techniques for biological research, available in most imaging platforms, allowing in depth studies at organ or cellular level with TPEM and subcellular level with EM. Recently the combination of these two techniques is of growing emphasis, allowing the acquisition at these two scales on the same sample. The development of this correlative technique pointed out the necessity to engineer new dyes allowing the induction of contrast in both methods on the same system. We describe here the preparation and characterization of core shell iron oxide nanoparticles (for EM contrast) conjugated to new functionalized two-photon sensitive fluorescent dyes (for TPEM contrast). These dyes showed astonishing contrast in EM and TPEM on HeLa cell cultures.
Keywords: Correlative light-electron microscopy, Two-photon microscopy, Electron microscopy, Core shell iron oxide nanoparticle, Diketodipyrrolopyrrole, Fluorescent Dyes, Multimodal fluorophore