Patent ID: 8034558

Claim:
A method for labelling and detecting a biological material, the method comprising: i) adding to a liquid containing said biological material a fluorescent dye of formula: wherein: groups R 2 and R 3 are attached to the Z 1 ring structure and groups R 4 and R 5 are attached to the Z 2 ring structure; Z 1 and Z 2 independently represent the atoms necessary to complete one ring, two fused ring, or three fused ring aromatic or heteroaromatic systems, each ring having five or six atoms selected from carbon atoms and optionally no more than two atoms selected from oxygen, nitrogen and sulphur; at least one of groups R 1 , R 2 , R 3 , R 4 and R 5 is the group -E-F where E is a spacer group having a chain from 1-60 atoms selected from the group consisting of carbon, nitrogen, oxygen, sulphur and phosphorus atoms and F is a target bonding group; when any of said groups R 2 , R 3 , R 4 and R 5 is not said group -E-F, said remaining groups R 2 , R 3 , R 4 and R 5 are independently selected from hydrogen, halogen, amide, hydroxyl, cyano, amino, mono- or di-C 1 -C 4 alkyl-substituted amino, sulphydryl, carbonyl, carboxyl, C 1 -C 6 alkoxy, acrylate, vinyl, styryl, aryl, heteroaryl, C 1 -C 20 alkyl, aralkyl, sulphonate, sulphonic acid, quaternary ammonium and the group —(CH 2 —) n Y; and, when group R 1 is not said group -E-F, it is selected from hydrogen, C 1 -C 20 alkyl, aralkyl and the group —(CH 2 —) n Y; Y is selected from sulphonate, sulphate, phosphonate, phosphate, quaternary ammonium and carboxyl; and n is an integer from 1 to 6; ii) incubating said dye with said target biological material under conditions suitable for labelling said biological material; and iii) detecting said labelled biological material by measurement of its fluorescence lifetime.