Ultrafast nonlinear multimodal metabolic imaging platform for studying aging and diseases

Abstract

Quantification of molecular colocalization is an essential issue in understanding many biological processes in living organisms. To measure the spatial distribution of multiple biomolecules, an ideal way is to image them one by one in the exact same region of interest and the same focus plane. To achieve this goal, we integrated multiple optical imaging modalities including stimulated Raman scattering (SRS), multiphoton fluorescence (MPF), and second harmonic generation (SHG) all together into one multimodal microscopy. We further combined deuterium oxide probing with stimulated Raman scattering (DO-SRS) for visualizing newly synthesized protein and lipid molecules, in addition to macromolecules (protein and lipid, NADH and Flavin, collagen) imaged with label free SRS, MPF, and SHG. We quantitatively measured the metabolic dynamics in cells and animals under various conditions, including HeLa cells grew in different serine concentrations, Drosophila ovaries in young and old individuals, and two different types of breast cancer tissues from xenograft mouse models. The results show the capabilities and advantages of this multimodal imaging system in accessing the spatial distributions of multiple molecules quantitatively.