Cyanine dyes

Abstract

A compound of the formula (I)wherein Z is O, S, or NRwherein Ris H or alkyl; R–Rare each independently H, alkyl, halo, carboxyl, amino, or SOCat, wherein Catis a cation and at least one of R–Ris SOCat; Rand Rare each H, alkyl, or optionally, together with the (a) group to which they are bonded, form a ring; m and n are each independently integers from 0 to 5; X and Y are each independently O, S, Se or CRR, wherein Rand Rare each independently alkyl, or optionally form a ring together with the carbon atom to which they are bonded; Rand Rare each independently alkyl, (CH)Ror (CH)R; wherein at least one of Rand R(CH)Rand wherein r is an integer from 1 to 50, and Ris a functional group that does not directly react with a carboxyl, hydroxyl, amino, or a thiol group, and Ris a functional group that can react with a carboxyl, hydroxyl, amino, or thiol group; and R–Rand R–Rare each independently H, alkyl, halo, amino, sulfonato, RCOOH, ROR, RSR, or RCOORwherein Ris a bond or alkylene and Ris alkyl, or optionally Rand Rtogether with the atoms to which they are bonded form an aromatic ring, or optionally Rand Rtogether with the atoms to which they are bonded form an aromatic ring. Methods of dye-labeling biomolecules with the compound of formula (I) and dye-labeled biomolecules are also provided.