LMI Seminar: Decoding the information contained in the fluorophore

Abstract:

The dipole radiation pattern changes when a fluorescent molecule comes close to the boundary between media of different refractive indices. Near-interface mole-cules emit mostly into the higher-index medium, mainly around the critical angle. The radiation pattern encodes information about the emitter distance, orientation, and the refractive index of the embedding medium.  The analysis of supercritical angle fluorescence on pupil-plane images can retrieve this information. Indeed, it has been applied for measuring the effective numerical aperture of high-NA detection optics, the axial fluorophore distance, as well as the orientation and rotational mobility of molecular dipoles. In more recent work we used it for combined fluorescence imaging and refractometry with subcellular resolution, and for the detection of metabolically active cancerous cells (Brunstein et al. 2017, Biohphs. J).