Congo red excellent quality manufacturer, exporter and supplier. Congo red is an organic compound, the sodium salt of 3,3%u2032-([1,1%u2032-biphenyl]-4,4%u2032-diyl)bis(4-aminonaphthalene-1-sulfonic acid. It is an azo dye. Congo red is water-soluble, yielding a red colloidal solution; its solubility is greater in organic solvents. However, the use of Congo red has long been abandoned, primarily because of its carcinogenic properties.

Technical Specifications:
C.A.S. No. 573-58-0
CI NO. 22120
M.F. C32H22N6Na2O6S2
M.W. 696.66gm/mole


Dye Content (by Spectrophotometry) >75%
Transition Range pH 3.0-5.2
  Violet-Orange Red
Solubility 0.1% (Dist. Water) Clear solution
Absorption Maximum (Dist.Water) ?max 495-499nm
Absorptivity (A1%, 1cm in Water, at ?max) >520
Loss On Drying (110°C) <5%
Suitability for microscopy Passes test

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