Ponceau S

  • 3-hydroxy- 4-( (2 -sulfo- 4-( (4- sulfophenyl) azo) phenyl) azo) - 2,7- naphthalenedisulfonic acid tetrasodium salt
  • C. I. 27195
  • Acid Red 112
  • C22H16N4O13S4 (acid)
  • C22H12N4Na4O13S4 ( tetrasodium salt)

Attention

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Ponceau S is a red azo dye which is often used on a nitrocellulose or PVDF membrane to stain proteins reversible.

Use

Western- blot of the colorant is used to check whether protein was transferred onto the membrane. Ponceau S reversibly binds to the positively charged amine groups of proteins. A Ponceau S staining is very easy to wash out with water to reuse the membrane, for example, for immunodetection with antibodies.

A common recipe for the coloring is 0.1% Ponceau S in 5% acetic acid or 2% Ponceau S in 30% trichloroacetic acid and 30% 5 -sulfosalicylic acid (2- hydroxy-5- sulfobenzoic acid ).

CAS registry number PubChem Dangerous Substances Directive (67/548/EEC)
656050
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