Novel linkers for linking a donor dye to an acceptor dye in an energy transfer fluorescent dye are provided. These linkers faciliate the efficient transfer of energy between a donor and acceptor dye in an energy transfer dye. One of these linkers for linking a donor dye to an acceptor dye in an energy transfer fluorescent dye has the general structure R.sub.21Z.sub.1C(O)R.sub.22R.sub.28 where R.sub.21 is a C.sub.1-5 alkyl attached to the donor dye, C(O) is a carbonyl group, Z.sub.1 is either NH, sulfur or oxygen, R.sub.22 is a substituent which includes an alkene, diene, alkyne, a five and six membered ring having at least one unsaturated bond or a fused ring structure which is attached to the carbonyl carbon, and R.sub.28 includes a functional group which attaches the linker to the acceptor dye.