Introduction:

Ponceau S is a water-soluble anionic diazo dye consisting of diazoaminoazobenzenedisulfonic acid and naphthol disulfonic acid coupled to a tetrasodium salt. Its molecular formula is C₂₂H₁₂N₄Na₄O₁₃S₄, and its molecular weight is 760.6. Ponceau S is negatively charged and can bind to positively charged amino acid residues, while Ponceau S can also bind to non-polar regions of proteins to form red bands.

Ponceau S staining solution can be used for protein detection on PVDF membrane, nitrocellulose membrane and cellulose acetate membrane, but not on nylon membrane. Transferred proteins (greater than 200 ng/band) appear as red bands on a pink background. Ponceau S staining is not only simple and fast, but also reversible. This staining method is particularly advantageous when the blot is to be reused for a second detection method such as immunoblotting.

• Staining is reversible: It can be washed with distilled water, PBS or other appropriate solutions until the background is clear after staining.
• Easy to use, low background, high sensitivity, long-term stable performance, clear and sensitive coloring, and the detection limit of protein is 250 ng.

Storage: Store at room temperature away from light, valid for 12 months.

Protocol (for reference only):

1. 1× Ponceau S staining solution can be used for membrane transfer directly. 10× Ponceau S staining solution should be diluted to 1× working concentration before use.
2. Dilute the 10× Ponceau S staining solution with the ratio of 10×Ponceau S staining solution: distilled water =1: 9 and mix well.
3. Immerse the PVDF membrane, nitrocellulose membrane or cellulose acetate membrane in 1× Ponceau S staining solution and shake at room temperature for 3-5 min or longer until clear bands appear.
4. Properly record or photograph the results.
5. Rinse 2~3 times with distilled water, PBS or other appropriate solution for 3~5min each time to remove Ponceau S.
6. Carry out subsequent western detection.

Notes:

1. This reagent is not suitable for the detection of proteins on nylon membranes.
2. For your safety and health, please wear a lab coat and disposable gloves for operation.
3. For research use only. Not for use in diagnostic procedures.