Ponceaue 4R interaction with protein, Nisin and BSA was concentration dependent and may be used for protein assay. As the dye binds with almost all the proteins and current methodology may be used for the estimation of proteins in various food systems. During the course of present work staining with ponceau 4R of resolved proteins on PAGE (poly acryl amide gel electrophorosis) was comparable with Coommassie Brilliant Blue R250. The Ponceaue 4R was highly sensitive, rapid and produced sharp red bands on the gel on 0.2% concentration. The effects of pH, concentration of proteins and dye were also investigated in various conditions which would help food processors to use a calculated amount of dye. The impact of tryptic digestibility on Ponceaue 4R -Protein Complexes (PPC) has illustrated that dye may safely be used without any adverse effect on the digestion of PPC.