Ponceau Staining Solution (also known as Ponceus) is a reagent widely used in molecular biology and biochemistry for the reversible staining of proteins transferred to nitrocellulose or PVDF membranes after gel electrophoresis, such as SDS-PAGE. It enables quick and sensitive visualization of protein bands to assess transfer efficiency and protein distribution without interfering with downstream applications like Western blotting or mass spectrometry. The solution is non-permanent, allowing easy destaining, and is compatible with various immunological detections. Its simplicity, cost-effectiveness, and high specificity make it an essential tool for routine protein analysis in academic and industrial laboratories.