Doubly Thiazole Orange-Labeled DNA for Live Cell RNA Imaging

Abstract

Abstract A hybridization-sensitive, quencher-free fluorescent probe for RNA detection has been designed using the concept of fluorescence quenching caused by the intramolecular excitonic interaction of fluorescence dyes. We synthesized a doubly thiazole orange-labeled nucleoside showing high fluorescence intensity for a hybrid with the target RNA and effective quenching for the single-stranded state. The probe was applied to living HeLa cells using microinjection to visualize intracellular mRNA localization. Immediately after injection of the probe into the cell, fluorescence from the probe hybridizing with the target RNA was observed. This fluorescence rapidly decreased upon addition of a competitor DNA. This probe realized a large, rapid, and reversible change in fluorescence intensity in sensitive response to the amount of target RNA, and facilitated spatiotemporal monitoring of the behavior of intracellular RNA.