Patent ID: 8586325

Claim:
A compound comprising a fluorogenic dye moiety of the formula: wherein: n is 0, 1, 2 or 3; n′ is 1, 2, 3, 4, or 5; m′ is 0 or 1; m″ is 1, when m′ is 0; m″ is 0, 2, 3 or 4, when m′ is 1; W is NH, O, or S; X is O or S; ψ comprises a biologically compatible counter ion; d is a number of ψ sufficient to render overall charge of the substrate neutral; R 8 and R 9 , in combination, form a fused aromatic ring, wherein the ring is optionally substituted by at least one substituent of a C1-C2 alkyl substituent, a C1-C2 alkoxy substituent, a C1-C2 alkyl-mercapto substituent, and a halogen substituent; and B is an enzyme substrate moiety capable of being cleaved by a caspase enzyme.