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 Hydrazide esters provide a convenient method for the labeling of free carbonyl groups of glycoproteins and carbohydrates. For maximum convenience, stable active hydrazide esters are supplied and stored as solid material.