Ponceau S (Acid Red 112) | High-Purity Protein Stain for Western Blotting | CAS 6226-79-5 | EU-Based Lab Supplier

Common Applications of Ponceau S

🧬 Protein electrophoresis stains

Classical red stain for visualizing proteins on nitrocellulose, PVDF, and cellulose membranes after transfer from SDS–PAGE gels. Gives fast, uniform bands so you can confirm the presence and distribution of protein before committing to antibody steps.

🧫 Membrane / blotting QC

Used as a quick, reversible stain for Western blots to verify transfer efficiency, detect uneven loading, and identify air bubbles or transfer artefacts. Rinses off easily with water or mild acid, allowing subsequent immunodetection on the same membrane.

📊 Lane loading control & documentation

Enables rapid visual comparison of protein loading between lanes, independent of antibodies. Many labs photograph Ponceau S–stained blots for records before destaining and probing.

🧪 General protein staining in teaching labs

Ideal for student practicals and teaching labs where quick, low-cost visualization of proteins is needed without permanent, silver- or Coomassie-level staining. Easy to prepare and to wash out, making it a good “first exposure” to blotting techniques.

🔁 Reversible pre-check before expensive reagents

Acts as a low-cost checkpoint: confirm the quality of transfer and band pattern before using costly primary and secondary antibodies or chemiluminescent substrates.

🌊 Buffer and transfer optimization

Useful for method development and troubleshooting of transfer conditions (time, voltage, buffer composition). Differences in band sharpness and intensity under Ponceau S can guide optimization.

🎓 Demonstrations of protein handling & immobilization

Simplifies live or classroom demos focused on how proteins migrate, bind to membranes, and can be visualized non-specifically, without going into full immunoassay workflows.

Spectral / Visual Properties

🎨 Colour: Bright red in acidic solution; bands appear red to pink-red on membranes.

📈 Absorbance (λₘₐₓ): Typically around ~520 nm in acidic aqueous solutions (exact peak shifts slightly with pH and buffer composition).

🧫 Behavior: Binds non-specifically but reversibly to a wide range of proteins immobilised on membranes. Can be largely removed by washing with water or dilute acid/alcohol mixtures, leaving the blot ready for downstream immunostaining.

For research and educational use only.

Not for diagnostic, therapeutic, cosmetic or food applications. Staining performance and spectral response depend on membrane type, buffer system, protein load and washing conditions. Always optimize for your own protocol and consult the SDS/CoA for your specific lot.