Deciphering single cell metabolism by coherent Raman scattering microscopy

•Metabolism is highly dynamic and intrinsically heterogeneous at the cellular level.•CRS microscopy visualizes metabolic activities of biomolecules in single live cells.•CRS study of single cell metabolism is facilitated by incorporation of Raman tags.•CRS study offers new insights into the role of cell metabolism in pathogenesis. Metabolism is highly dynamic and intrinsically heterogeneous at the cellular level. Although fluorescence microscopy has been commonly used for single cell analysis, bulky fluorescent probes often perturb the biological activities of small biomolecules such as metabolites. Such challenge can be overcome by a vibrational imaging technique known as coherent Raman scattering microscopy, which is capable of chemically selective, highly sensitive, and high-speed imaging of biomolecules with submicron resolution. Such capability has enabled quantitative assessments of metabolic activities of biomolecules (e.g. lipids, proteins, nucleic acids) in single live cells in vitro and in vivo. These investigations provide new insights into the role of cell metabolism in maintenance of homeostasis and pathogenesis of diseases.