Atto 700 belongs to a new generation of fluorescent labels. The dye is designed for application in the area of life science, e.g. labeling of DNA, RNA or proteins. Characteristic features of the label are strong absorption, high fluorescence quantum yield, excellent thermal and photo-stability, very good water solubility and very little triplet formation. Atto 700is a zwitterionic dye with a net electrical charge of zero. The fluorescence is efficiently quenched by electron donors like guanine, tryptophan, etc. The azide modification is suitable for reactions with alkyne groups (Huisgen reaction - “Click Chemistry“).