Molecular Weight: 696.66 g/mol

Congo Red Chemical Structure
Chemical Structure
Check the Congo Red product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.

How to Prepare Stock Solution?

Concentration Volume Mass
🧮 Molarity Calculator

Solubility

Batch:
All in vitro solubility values are batch-tested experimental data (non-literature values).
Solvent Solubility & Note
DMSO 100 mg/mL (143.54 mM)
(Moisture-contaminated DMSO may reduce solubility. Use fresh, anhydrous DMSO. The recommended stock concentration is 10 mM in DMSO.)
FAQ
Q: Why does a DMSO stock precipitate in media/saline?
A: It is caused by unheated aqueous media (supersaturation), local solvent shock, or incorrect mixing sequence.
How to fix it?
  • Preheat media/saline to 37°C.
  • Mix rapidly (pipette/vortex) upon addition.
  • For complex mixes, always add the aqueous phase last.
  • Re-dissolve minor precipitates with a 37°C water bath and sonication (≤30 min).

Chemical Information

IUPAC Name disodium;4-amino-3-[[4-[4-[(1-amino-4-sulfonatonaphthalen-2-yl)diazenyl]phenyl]phenyl]diazenyl]naphthalene-1-sulfonate
CAS Number 573-58-0
Molecular Formula

C32H22N6Na2O6S2
Molecular Weight (MW) 696.66
SMILES C1=CC=C2C(=C1)C(=CC(=C2N)N=NC3=CC=C(C=C3)C4=CC=C(C=C4)N=NC5=C(C6=CC=CC=C6C(=C5)S(=O)(=O)[O-])N)S(=O)(=O)[O-].[Na+].[Na+]
InChIKey IQFVPQOLBLOTPF-UHFFFAOYSA-L

Jump to

Note: Technical data last updated: Sep 1, 2026.