A Rapid Synthesis of Nuclear-Staining Small Fluorescent Molecules for Brain Imaging

Fluorescent probes are important tools in cellular imaging. However, many readily available small-molecule imaging probes are either cytotoxic or easily photobleached and thus not compatible with lengthy live cell or tissue-imaging experiments. One particularly limited field of application is neuroscience, in which small-molecule probes for live cell imaging at the brain tissue level are highly scarce. Here, we describe a rapid synthetic route to generate a series of nuclear stains that enable experiments with live brain cells (i.e., water solubility, cell permeability, high quantum yield, high photostability, and most important, negligible cytotoxicity). As a proof of principle, we demonstrate that these probes are compatible with ex vivo and in vivo nuclear labeling experiments, including retrograde transport to monitor and map certain brain regions of the mouse model. The structural versatility and superior non-cytotoxic properties of these probes may suggest their potential use in labeling and tracing of neuronal populations. [Display omitted] Rapid synthesis of nuclear-staining small-molecule NeuroX dyesDevelopment of photostable, noncytotoxic, water-soluble, cell-permeable NeuroX dyesImaging studies of NeuroX dyes both in vitro and in vivoRetrograde labeling with NeuroX probes in mouse brain High photostability, high quantum yield, non-cytotoxicity, water solubility, and cell permeability are critical for long-term imaging experiments in live cells and tissues. Suh et al. report the rapid synthesis of nuclear staining NeuroX dyes and their imaging applications for live cells and tissues both in vitro and in vivo.