Patent ID: 7855293

Claim:
A fluorescent dye having a formula (I) wherein X is O, or and T is n′ is an integer which is 0, 1, 2, or 3 and W − is a counter ion, wherein at least one of the substituents R 1 , R 10 , R 6 -R 9 and R 18 to R 19 is a chemical reactive group (Rx) for covalent coupling to a target molecule which is selected from the group consisting of: wherein n is 1-8; and wherein at least one of the substituents R 1 , R 4 , R 10 , R 13 , R 6 to R 9 and R 18 to R 19 is a hydrophilic group to promote water solubility selected from the group consisting of sulfonic acids and sulfonates, having a formula with r equal to 0 to 8 and M + is a metal cation; and the other substituents R 1 to R 19 are independently selected from the group consisting of H, alkyl (C 1 -C 10 ), alkoxy (C 1 -C 10 ), trifluoromethyl, nitro, and halogen.