Fluorescent kapakahines serve as non-toxic probes for live cell Golgi imaging.

AIMS: There is an ongoing need for fluorescent probes that specifically-target select organelles within mammalian cells. This study describes the development of probes for the selective labeling of the Golgi apparatus and offers applications for live cell and fixed cell imaging. MAIN METHODS: The kapakahines, characterized by a common C(3)-N(1') dimeric tryptophan linkage, comprise a unique family of bioactive marine depsipeptide natural products. We describe the uptake and subcellular localization of fluorescently-labeled analogs of kapakahine E. Using confocal microscopy, we identify a rapid and selective localization within the Golgi apparatus. Comparison with commercial Golgi stains indicates a unique localization pattern, which differs from currently available materials, therein offering a new tool to monitor the Golgi in live cells without toxic side effects. KEY FINDINGS: This study identifies a fluorescent analog of kapakahine E that is rapidly uptaken in cells and localizes within the Golgi apparatus. SIGNIFICANCE: The advance of microscopic methods is reliant on the parallel discovery of next generation molecular probes. This study describes the advance of stable and viable probe for staining the Golgi apparatus.