Lyso-Tracker Red is a fluorescent probe used to label lysosomes in live cells, commonly used in biomedical research involving intracellular acidic compartments. Structurally, it is a weakly basic compound that can easily penetrate the cell membrane and selectively accumulate in acidic organelles, particularly lysosomes, thanks to its protonation and retention mechanism in the acidic intracellular environment. After accumulation, the probe emits red fluorescence, facilitating the visualization and analysis of lysosome distribution, morphology, and activity via fluorescence microscopy or flow cytometry. Compared to traditional lysosomal markers such as neutral red or acridine orange, Lyso-Tracker Red exhibits high specificity for lysosomal compartments. The probe is provided in a 1 mM DMSO stock solution and is typically applied at nanomolar concentrations for the visualization and tracking of lysosomal dynamics in live cell experiments, but it is not used for staining fixed cells.

BV2 Cells stained with Lyso-Tracker Red