Patent ID: 7402671

Claim:
An energy transfer dye comprising: a donor dye which is a member of a class of dyes having a coumarin or pyrene ring structure; an acceptor dye capable of absorbing excitation energy emitted by the donor dye and emitting light in response, the acceptor dye having an emission maxima greater than about 500 nm; and a linker linking the donor dye to the acceptor dye which comprises a five or six membered ring selected from the group consisting of cyclopentene, cyclohexene, cyclopentadiene, cyclohexadiene, furan, thiofuran, pyrrole, isopyrole, isoazole, pyrazole, isoimidazole, pyran, pyrone, benzene, pyridine, pyridazine, pyrimidine, pyrazine, oxazine, indene, benzofuran, thionaphthene, indole and naphthalene.