ATTO 655 belongs to a new generation of fluorescent labels. Characteristic features of the label are strong absorption, high fluorescence quantum yield, high thermal and photostability, exceptionally high stability towards atmospheric ozone, excellent water solubility, and only little triplet formation.

ATTO 655 and its derivatives are supplied as crystalline solids. After coupling to a substrate the dye moiety is electrically neutral. For details of coupling see our recommended labeling procedure (PDF). The fluorescence is excited most efficiently in the range 625 - 660 nm.