PONCEAU S excellent quality manufacturer, supplier and exporter. PONCEAU S is a sodium salt of a diazo dye of a light red color, that may be used to prepare a stain for rapid reversible detection of protein bands on nitrocellulose or polyvinylidene fluoride (PVDF) membranes (Western blotting), as well as on cellulose acetate membranes. It can be used to locate proteins or evaluate efficiency of transfer. Reversible staining with ponceau S has also been validated as an alternative to actin probing as a loading control. This stain can also be used as a fiducial marker in mass spectrometric imaging.