Patent ID: 8771646

Claim:
A method of in vivo optical imaging, the method comprising: (a) administering to a subject a biocompatible fluorescent molecule comprising one or more biomolecules covalently linked to a fluorescent compound represented by formula (2): or a salt thereof, wherein: X is independently selected from the group consisting of C(CH 2 Y 1 )(CH 2 Y 2 ), O, S, and Se; Y 1 and Y 2 are independently selected from the group consisting of H, C 1 -C 20 aliphatic group and a C 1 -C 20 aliphatic group wherein one or more methylene groups are replaced by O, S, or NH; W represents a benzo-condensed ring or a naphtho-condensed ring; R 1 is selected from the group consisting of H, (CH 2 ) x CH 3 , (CH 2 ) n SO 3 − and (CH 2 ) n SO 3 H, wherein x is an integer selected from 0 to 6 and n is an integer selected from 2 to 6; R 4 is selected from the group consisting of H, (CH 2 ) x CH 3 , (CH 2 ) n SO 3 − and (CH 2 ) n SO 3 H, wherein x is an integer selected from 0 to 6 and n is an integer selected from 2 to 6; R 2 and R 3 are independently selected from the group consisting of H, carboxylate, carboxylic acid, carboxylic ester, amine, amide, sulfonamide, hydroxyl, alkoxyl, a sulphonic acid moiety and a sulphonate moiety; Q is a heteroaryl ring substituted with —CO 2 H, —C(O)-halide, —C(O)O-benzotriazolyl, —C(O)O—N-succinimidyl, —C(O)O-tetrafluorophenyl, —C(O)O-pentafluorophenyl, —C(O)O-imidazolyl, or —C(O)O-p-nitrophenyl; or Q is selected from the group consisting of Q is a 6-membered heteroaryl ring substituted with —C(═O)R**, wherein R** is a saturated straight-chain hydrocarbon, a branched hydrocarbon, or a cyclic hydrocarbon; or Q is a carboxyl or carbonyl substituted 6-membered heteroaryl ring selected from the group consisting of pyridine, pyrimidone, pyrazine and pyridazine; and wherein the biomolecule is chemically linked to the fluorescent compound via reaction with Q thereby producing the biocompatible fluorescent molecule; (b) allowing time for the biocompatible fluorescent molecule to distribute within the subject or to contact or interact with a biological target within the subject; (c) illuminating the subject with light of a wavelength absorbable by the biocompatible fluorescent molecule; and (d) detecting the optical signal emitted by the biocompatible fluorescent molecule.