Development and characterization of BODIPY-derived tracers for fluorescent labeling of the endoplasmic reticulum

Visualization of the structure of the Endoplasmic Reticulum (ER) in living cells is important for the understanding of its function. Here we synthesized a library of BODIPY labeled 8 hydroxyquinoline derivatives and evaluated their spectroscopic properties, cytotoxicity, and intracellular localization. The compounds were easily obtained in 34 – 80% yield. Based on the spectral properties and low cytotoxicity, we selected the quinolin-8-yl pentanoate derivative 17 for in vivo labeling of the ER. Fluorescence staining of the ER was evaluated by comparison with a commercial ER tracker. The molecules here developed are smaller than the alternatives commercially available while still presenting a high specificity towards the ER.