Lysosomes have long been considered static organelles, ensuring the degradation and recycling of cellular wastes. However, they are all but static, and their activity, intracellular distribution, number, as well as their capacity to welcome cargo are regulated by various signaling pathways and cellular needs (Baabio & Bonifacino, 2019; Bright, Davis, et al., 2016; Huotari & Helenius, 2011).

Lysosomes substantially contribute to tissue and organ homeostasis by clearing damaged cell organelles and proteins. Cumulating knowledge expands the number of diseases directly and indirectly linked to their dysfunction, from rare lysosomal storage disorders (Marques & Saftig, 2019) to more frequent cancers, metabolic and neurodegenerative diseases (Fraldi, Klein, et al., 2016; Gilleron, Gerdes, et al., 2019; Kimmelman & White, 2017).

Monitoring lysosome biogenesis, plasticity, mobility within the cell, and turnover, as well as quantifying cargo delivery to and accumulation within endolysosomes, is instrumental in characterizing lysosome-driven pathways at the molecular level and monitoring consequences of genetic or environmental modifications.