Aminooxy CF660R (aka CF660R hydroxylamine or CF660R aminooxyacetamide) is our superior far red fluorescent dye CF660R with an aminooxy reactive group, which can be used to label a target molecule with an aldehyde or ketone group. Aminooxy group readily reacts with an aldehyde or ketone group to form a stable linkage without the use of a reducing agent. CF660R is a bright and exceptionally photostable dye that absorbs at 663 nm and emits fluorescence at 682 nm in the borderline spectral region between far-red and near-IR. CF660R is ideal for confocal microscopy, where it can add a long wavelength color in multi-color imaging.