LysoTracker Deep Red stain is a cell-permeable, non-fixable red fluorescent dye that can detect intracellular acidic Compartments such as lysosomes are stained. Deep Red stain has a maximum excitation and emission wavelength of 647/668 nm and can be efficiently excited using Cy5 filters. LysoTracker probes are available in a variety of fluorescent colors.

Simple, highly specific one-step staining and tracking of acidic organelles
LysoTracker probes consist of a fluorophore conjugated to a weak base and are active only in neutral Partially protonated under pH conditions. In the neutral charge state, LysoTracker probes diffuse freely across the intact plasma membrane of living cells. Due to the inherent acidity within lysosomes, weakly basic groups become protonated upon diffusion into lysosomes. In this charged state, the probe cannot easily diffuse across organelle membranes, providing local accumulation for unique staining of acidic organelles such as lysosomes. LysoTracker probes are effective at nanomolar concentrations, are highly selective for acidic organelles, and provide simple one-step staining that does not rely on antibody detection.

Lysosomes are acidic due to the production and storage of digestive enzymes (hydrolases). The acidic environment of lysosomes can degrade carbohydrates, lipids, nucleic acids, and peptides. Extracellular proteins, viruses, or bacteria can also be internalized and transported to lysosomes for degradation via the lysosomal proteolytic pathway. Furthermore, misfolded proteins or damaged organelles become targets for lysosomal degradation through induction of autophagy. Autophagy is important for cell differentiation, survival during nutrient deprivation, and normal growth control. A variety of acidic environment-dependent probes exploit the inherent acidity within lysosomes, as well as any changes in pH during biosynthesis or pathogenesis. LysoTracker products provide fluorescent detection for staining live cells in acidic environments and can also be used to label and track acidic organelles such as lysosomes.