ATTO 565 is a new fluorescent label belonging to the class of Rhodamine dyes. The dye shows strong absorption, high fluorescence quantum yield, high thermal and photostability, and only little triplet formation.

ATTO 565 is supplied as a crystalline 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 is excited most efficiently in the range 545 - 575 nm.

As supplied ATTO 565 consists of a mixture of two isomers with practically identical absorption and fluorescence. However, on request the dye can also be supplied in isomeric purity.