Compounds having the general of formula I and/or formula II TABLE-US-00001 wherein R.sup.1 and R.sup.2 are the same or different and are independently selected from the group consisting of --H, --C.sub.1-C.sub.18-alkyl or -.omega.-sulfoalkyl; X and Y are the same or different and are independently selected from the group consisting of --O.sup.-, --OH, --SH, --NH--NH.sub.2, --F, --Cl, --Br, --I, --O-Su (succinimidyl/sulfosuccinimidyl), --O-STP (4-sulfo-2,3,5,6-tetrafluorophenyl), --O-TFP (2,3,5,6-tetrafluorophenyl), --O-benzotriazole, -benzotriazole, --NR--CO--CH.sub.2--I, --NR.sub.2, --NR-biomolecule, --NR-L-COO.sup.-, --NR-L-COOH, --NR-L-COO-Su, --NR-L-COO-STP, --NR-L-COO-TFP, --NR-L-CONR.sub.2, --NR-L-CO-biomolecule, --NR-L-CO--NH--NH.sub.2, --NR-L-OH, --NR-L-O-phosphoramidite, --NR-L-CHO, --NR-L-maleimid, or --NR-L-NH--CO--CH.sub.2--I; where R is equal to R.sup.1 and R.sup.2 and L is selected from the group consisting of a divalent linear (--(CH.sub.2).sub.o--, o=1 to 15), crossed, or cyclic alkane group that can be substituted by at least one atom selected from the group consisting of oxygen, substituted nitrogen, and/or sulfur, and the biomolecule is a protein, antibody, nucleotide, oligonucleotide, biotin, or hapten; Z is --O.sup.- or OH; U is --O.sup.-, --OH, or NH-L-SO.sub.2Z; Kat is Li, Na, K, ammonium (mono-, di- or trialkyl) or another cation; An is F, Cl, Br, I, BF.sub.4, ClO.sub.4, CH.sub.3CO.sub.2, CF.sub.3CO.sub.2 or another anion; m is an integer from 1-6 necessary to compensate the negative or positive charge from the dye moiety in formula I or formula II; and n is an integer from 0-12;compositions containing these compounds, and methods using these compounds, are disclosed.