Targeted and specific labeling of amine residues on antibodies, peptides or oligonucleotides. Bulk packs available for greatest economy. Example protocols included with each dye pack. Narrow excitation and emission bands result in discrete signals from each fluor Minimal crosstalk provides high accuracy and enables multiplexing. The packs contain derivitized CyDyes that carry only one reactive group on each dye molecule for accurate labeling of amine groups, for example on antibodies, peptides, or oligonucleotides.