Visualizing intracellular trafficking using label-free dynamic scattering-particle localization interference microscopy (DySLIM)

Intracellular cargo trafficking ensures precise delivery of essential cellular components crucial for cellular functions. Early studies used biochemical and genetic methods to explore its molecular mechanisms, but struggled to capture its dynamic nature. Fluorescent protein tagging revolutionized our ability to monitor cargos' lifecycles, yet challenges remain, such as understanding their navigation through crowded cellular environments. Interferometry-based imaging can address these issues, offering transformative insights into intracellular traffic dynamics. Here, we introduce “Dynamic Scattering-particle Localization Interference Microscopy (DySLIM)”, a high-speed, label-free imaging technique that provides high sensitivity for quantitative insights into cargo transport dynamics. Our study demonstrates how cargos navigate dense environments using strategies like collective migration and hitchhiking, akin to urban traffic management. We also emphasize the complementary benefits of DySLIM alongside chemical-selective fluorescent methods, providing a comprehensive view of intracellular logistics.