Invitrogen™ LysoTracker™ Red DND-99, special packaging

LysoTracker Red DND-99 is a cell-permeable red fluorescent dye that stains acidic compartments within a cell, such as lysosomes. Red DND-99 has an excitation and emission maximum of 577/590 nm and can be efficiently excited using a TRITC filter. LysoTracker probes are available in a variety of fluorescent colors. Although it does not crosslink with cells, LysoTracker Red DND-99 shows transient retention after methanol-free formaldehyde fixation for a short period of time.

Simple, highly specific, one-step staining and tracking of acidic organelles
LysoTracker probes consist of a hydrophobic fluorophore linked to a weak base that is only partially protonated at neutral pH. In a neutrally charge state, LysoTracker probes can freely diffuse across intact plasma membranes of live cells. Due to the inherently acidic properties within the lysosome, upon diffusion into the lysosome the weakly basic moiety is protonated. In this charged state, the probe does not readily diffuse across the organelle membrane, providing a localized accumulation for distinct staining of acidic organelles such as lysosomes. Effective at nanomolar concentrations, LysoTracker probes are highly selective for acidic organelles and provide simple one-step staining that does not rely on antibody detection.

Lysosomes are acidic in nature due to the production and storage of digestive enzymes (hydrolases). The acidic environment of lysosomes enables degradation of carbohydrates, lipids, nucleic acids, and peptides. Extracellular proteins, virus or bacteria can also be internalized and trafficked to the lysosome for degradation via the lysosomal proteolysis pathway. In addition, misfolded proteins or damaged organelles become targets for lysosomal degradation via the induction of autophagy. Autophagy is important for cellular differentiation, survival during nutrient deprivation, and normal growth control. The inherent acidic nature within lysosomes, and any change of pH during biosynthesis or pathogenesis, can be exploited by various probes that respond to an acidic environment. LysoTracker products provide fluorescence detection for live-cell staining of acidic environments and can be used for labeling and tracing acidic organelles such as lysosomes.