Patent ID: 8309695

Claim:
A labeling reagent of formula (A): in which: R 1 represents a detectable label or at least two detectable labels linked to one another by at least one multimeric structure, R 2 and R 3 represent, independently of one another: H, NO 2 , Cl, Br, F, I, R 4 , OR, SR, NR 2 , R, NHCOR, CONHR or COOR, with R being alkyl or aryl, and R 4 represents a detectable label or at least two detectable labels linked to one another by at least one multimeric structure, L is a linker arm comprising a linear chain of at least two covalent bonds, n is an integer from 1 to 20, A is a linker arm comprising at least one covalent double bond allowing the conjugation of the diazo function with the aromatic ring, and u is an integer between 0 and 2.