Coherent vibrational imaging for living cells

Abstract

Innovations in optical spectroscopy and microscopy have revolutionized our understanding in biol. systems at subcellular levels. While fluorescence microscopy with versatile fluorescent probes is widely popular for biomedical research, vibrational microscopy with rich chem. information is less explored. Here, I present two chem. imaging strategies addressing two fundamental challenges in optical bio-imaging, resp. First, we devised a live-cell Bioorthogonal Chem. Imaging platform suited for probing the metabolic dynamics of small bio-mols., which cannot be effectively labeled by bulky fluorophores. This scheme couples the emerging stimulated Raman scattering (SRS) microscopy with small vibrational tags including stable isotopes and triple bonds. Second, we developed a super-multiplex optical imaging technique enabled by resonant SRS microscopy of a newly designed palette of vibrational dyes. This work allows for simultaneous imaging of a large no. of mol. species in live cells and tissues with high sensitivity and specificity, bridging imaging and omics paradigms. Both phys. and chem. principles underlying the optical microscopy will be presented, as well as the exciting biomedical applications including DNA replication, protein synthesis, cancer metab., drug trafficking and neuronal metab.