Lipid droplet labeling

BODIPY493/503 methyl bromide is a BODIPY dye. BODIPY dye is a small molecule dye with strong ultraviolet absorption ability, its fluorescence peak is relatively sharp, and the quantum yield is high. They are relatively insensitive to the polarity and pH of the environment and are relatively stable under different physiological conditions. Due to its structural asymmetry, BODIPY derives a variety of structural products. BODIPY lipid droplet dyes can well pass through the cell membrane into the cell, and localize the neutral lipids in the cell to specifically stain the lipid droplets, which can be used for labeling of live cells and fixed cells . Maximum excitation/emission wavelength: 493/503 nm .

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].

DXB-NIR is a push-pull dioxaboron fluorescent probe with solvatochromic properties, featuring high fluorescence brightness, photostability, and a large two-photon absorption cross-section. DXB-NIR exhibits Ex/Em of 550/620–780 nm (with two-photon excitation at 930 nm). DXB-NIR quantifies local polarity via the intensity ratio I (>640)/I (<640) between the far-red channel (<640 nm) and the near-infrared channel (>640 nm), and it can simultaneously label the plasma membrane, endoplasmic reticulum, and lipid droplets in live cells. DXB-NIR monitors the increase in local polarity of various cell compartments under conditions of cholesterol depletion, starvation, and oxidative stress. DXB-NIR can be used for polarity imaging of biological membranes and lipid droplets, as well as studies related to cellular stress .