ATTO 495 is a new fluorescent label derived from the well-known dye Acridine Orange. Characteristic features of the label are strong absorption, high fluorescence quantum yield, and high thermal and photostability. At low temperatures or embedded in a polymeric matrix the dye shows intense after-glow (phosphorescence).

ATTO 495 is a cationic dye and is supplied as a crystalline solid in form of a solvent-free perchlorate salt. The dye is moderately hydrophilic. Its NHS-ester and maleimide show excellent solubility in polar solvents like DMF, DMSO or acetonitrile. For details of coupling see our recommended labeling procedure (PDF). The fluorescence can be excited efficiently in the range 465 - 510 nm.