Sulfo ICG bis-NHS ester

Sulfo ICG bis-NHS ester is a derivative of Indocyanine green (ICG) that contains sulfonic acid ions. This compound is employed in the labeling of proteins, amine-modified oligonucleotides, and other primary amine (R-NH2) containing molecules.

CC1(C2=C(C=CC(=C2)C(=O)OC3C(=O)CCC3=O)[N+](=C1/C=C/C=C/C=C/C=C/4\C(C5=C(N4CCCCS(=O)(=O)[O-])C=CC(=C5)C(=O)ON6C(=O)CCC6=O)(C)C)CCCCS(=O)(=O)[O-])C.[Na+]