Indigo carmine

860-22-0

sodium (E)-3,3'-dioxo-[2,2'-biindolinylidene]-5,5'-disulfonate

indigotine; 5;5′-indigodisulfonic acid sodium salt; Brilliant Indigo

0.98

insoluble in EtOH; ≥83.6 mg/mL in DMSO; ≥83.9 mg/mL in H2O

O=C(C1=C(N/2)C=CC(S([O-])(=O)=O)=C1)C2=C3C(C(C=C(S([O-])(=O)=O)C=C4)=C4N\3)=O.[Na+].[Na+]

C16H8N2Na2O8S2

466.35

Blue ice

Store at -20°C.