Distinction between glycomacropeptide and β-lactoglobulin with 'stains all' dye on tricine SDS-PAGE gels

Identification of glycomacropeptide (GMP) and beta-lactoglobulin (beta-lg) present in cheese whey is difficult on SDSPAGE due to their close proximity during electrophoresis and poor sensitivity of commonly used staining dye 'coomassie brilliant blue' (CBB) towards GMP. A simple method has been developed for the detection of GMP and beta-lg by staining acrylamide gel after tricine SDS-PAGE using cationic 'stains all' dye. After staining and destaining major whey proteins, viz.a-lactalbumin (a-la) and beta-lg appear red while GMP stains blue. The method can be used for the identification of these macromolecules in cheese whey and the detection of adulteration of milk with rennet whey.

Automated summary

A new method has been developed for the detection of glycomacropeptide and beta-lactoglobulin in cheese whey, using cationic 'stains all' dye after tricine SDS-PAGE, overcoming the poor sensitivity of common staining dye 'coomassie brilliant blue' towards glycomacropeptide.