Organelle-specific fluorescent probes for live imaging at the nanoscale

Intracellular organelles are structures within cells that compartmentalize biochemical reactions for advanced cellular functions. Historically, synthetic dyes that target various cellular targets have been the mainstay for modern cell biology, which are subsequently supplemented by genetically encodable fluorescent proteins. Recently, the optically privileged organic dyes have rejuvenated as indispensable tools for live-cell super-resolution (SR) imaging, including self-targeting probes for organelle labeling and self-labeling ligands that label genetically encoded protein tags (i.e., SNAP and Halo tags). In this review, we provide an overview of recent developments in design strategies and bioimaging applications of synthetic fluorescent probes for imaging organelles. We aim to provide a fluorescent dye-selection guide for cell biologists, while also offering an outlook on the potential directions of future research.