Ponceau S staining solution is used in electrophoresis studies and is designed for rapid staining of protein bands on nitrocellulose or Western blots. It is also for staining protein on cellulose acetate membranes. It may be employed for the purified fibrinolytic enzyme (CK) for analysis of N-terminal amino acid sequence of the first 14 residues of CK by a protein sequencer. This solution on nitrocellulose and PVDF is reversible by washing the stained membrane with 0.1M NaOH for 1 minute. The stained and destained membrane can then be immunologically detected (Western blotting).
Ponceau S solution has a formula of 0.1% (w/v) in 5% acetic acid and a refractive index of n20D 1.34.
Protocol: Wash the blot once with Ponceau S staining solution and incubate for 5-15 min at room temperature with agitation. Destain blot in multiple changes of PBS. Mark the position of molecular standards and transfer proteins required.