Specific Fluorescent Probes for Imaging DNA in Cell-Free Solution and in Mitochondria in Living Cells

New styryl dyes consisting of N-methylpyridine or N-methylquinoline scaffolds were synthesized, and their binding affinities for DNA in cell-free solution were studied. The replacement of heterocyclic residue from the pyridine to quinoline group as well as variation in the phenyl part strongly influenced their binding modes, binding affinities, and spectroscopic responses. Biological experiments showed the low toxicity of the obtained dyes and their applicability as selective dyes for mitochondria in living cells.

Automated summary

This study synthesized new styryl dyes with N-methylpyridine or N-methylquinoline scaffolds and examined their binding affinity for DNA in cell-free solution. The substitution of heterocyclic residue from pyridine to quinoline and variation in the phenyl part greatly influenced their binding modes, binding affinities, and spectroscopic responses. Biological experiments demonstrated the low toxicity of the synthesized dyes and their ability to selectively stain mitochondria in living cells.