The spectrum of VivoTrack 680 is 680nm a far-red and near-infrared emitting dye which is ideal for fluorescence measurements vivoNIR imaging experiments. It is wide used in fluorescence imaging and other fluorescence-based biochemical analysis. It is a water soluble and hydrophilic dye near infrared fluorescent cell labeling agent that can label a variety of cell types. As cell migration is critical for many important in vivo biological functions, this labeling approach has the potential to provide a useful tool for research in inflammation, immunology and stem cells The dye has four sulfo groups which give it a hydrophilic negative charge at physiological pH values.