BODIPY-aza-indole derivate complex as a selective fluorescent sensor for autolysosomes detection

Autophagy is a process of removal and degradation of unneeded or damaged cellular components, which plays an essential role in several physiological processes and associated diseases or ageing. Despite its importance, a simply applicable selective fluorescent dye able to specifically stain autolysosomes as a particular component of autophagy does not exist. Addressing this challenge, we present a new BODIPY-aza-indole complex (BODIPY-AZD-1) as a fluorescent dye selectively staining autolysosomes and distinguish them from lysosomes and autophagosomes. Taking advantage of BODIPY, this compound has excellent fluorescent properties, it is resistant to photobleaching, it is not phototoxic, and it is compatible with live-cell, time-lapse, and super-resolution microscopy and fixation. Due to the simple staining procedure and non-toxicity, we suggest this compound for studies of later phases of autophagy as well as for observation of autolysosome physiology in live and/or fixed cells.