DNS-M

Dansyl-morpholine (DNS-M) is a Fluorescent probe for lipid droplet imaging, cancer cell discrimination, and real-time tracking of lipid droplet dynamics. As a solvatochromic probe with a donor-π-acceptor structure, it relies on hydrophobic interaction for its mechanism of action: its good lipophilicity, confirmed by an oil-water partition coefficient LogP = 2.35, allows it to rapidly penetrate cell membranes, and it specifically localizes to the hydrophobic core of lipid droplets; its fluorescence is strongly enhanced in the nonpolar environment of lipid droplets, while it emits very weak fluorescence in polar environments like PBS buffer, and it exhibits a bathochromic shift in emission wavelength with increasing solvent polarity. It has negligible cytotoxicity, with cell viability remaining over 95% after 24-hour incubation with 100 μM of the probe, and it possesses excellent photostability, retaining over 97% of initial fluorescence intensity after 60 continuous laser scans. For cell imaging applications, its excitation/emission wavelengths for lipid droplet labeling are Ex/Em = 405/480−540 nm, and in a simulative lipid environment O/W emulsion, it has an excitation wavelength of ~346 nm and emission wavelength of ~500 nm, giving a Stokes shift of 154 nm[1].