Stimulated Raman Scattering DOI: 10.1002/anie.201400328 Live-Cell Stimulated Raman Scattering Imaging of Alkyne-Tagged Biomolecules**

Abstract: Alkynes can be metabolically incorporated into biomolecules including nucleic acids, proteins, lipids, and glycans. In addition to the clickable chemical reactivity, alkynes possess a unique Raman scattering within the Raman-silent region of a cell. Coupling this spectroscopic signature with Raman microscopy yields a new imaging modality beyond fluorescence and label-free microscopies. The bioorthogonal Raman imaging of various biomolecules tagged with an alkyne by a state-of-the-art Raman imaging technique, stimulated Raman scattering (SRS) microscopy, is reported. This imaging method affords non-invasiveness, high sensitivity, and molec-ular specificity and therefore should find broad applications in live-cell imaging. The alkyne has been used as a bioorthogonal chemical reporter that can be metabolically incorporated into variou