Patent ID: 8415472

Claim:
Water-soluble photochromic compounds for labeling biomolecules, which are represented by the following formula 1: wherein, P is a photochromic molecule selected from the group consisting of compounds represented by the following formulas 3-10 and isomers thereof, L is (CH 2 CH 2 O) n , where n is an integer ranging from 1 to 100, M is a functional group binding selectively to biomolecules, K is a fluorescent substance or an L, L-M or L-M-fluorescent substance, and X is selected from the group consisting of O, S, NH, and CH 2 , wherein, in the formula 3 and 4, R is a bond or a C 1 -C 3 alkylene group which is unsubstituted or substituted with an oxygen or fluorine atom, Y is independently an oxygen, nitrogen or sulfur atom, and Z is a methylene group or a carbonyl group, which are unsubstituted or substituted with fluorine.