Patent ID: 8552027

Claim:
A composition comprising a reporter compound having the formula: and its salts, or and its salts, where: n is an integer from 0 to 3; each R 1 independently is —H, a linked reactive group, a linked ionic group, a linked conjugated substance, or an alkyl group optionally substituted by 1-3 heteroatoms independently selected from the group of N, O, and S; Z is each R ι independently is —H, a linked reactive group, a linked ionic group, a linked conjugated substance, or an alkyl group optionally substituted by 1-3 heteroatoms independently selected from the group of N, O, and S; each R 3 independently is —H, a sulfo group, or an alkyl group optionally substituted by 1-3 heteroatoms independently selected from the group of N, O, and S; each R A independently is —H, or an alkyl group optionally substituted by 1-3 heteroatoms independently selected from the group of N, O, and S; each R P independently is —H, a linked alkyl phosphonate group, a linked substituted alkyl phosphonate group, a linked reactive group, a linked ionic group, a linked conjugated substance, or an alkyl group optionally substituted by 1-3 heteroatoms independently selected from the group of N, O, and S; wherein at least one R P is a linked alkyl phosphonate group, or a linked substituted alkyl phosphonate group; and wherein at least one of R 1 and R 3 contains a sulfo group.