When a food scientist needs to prove a specific protein is present, Western blotting is a go-to method. Proteins are first separated by size on a gel, then transferred — blotted — onto a membrane such as nitrocellulose or PVDF, where they stick in the same pattern they held on the gel. Labelled antibodies that recognise only the target protein then light it up; alternatively, an unlabelled primary antibody binds first and a labelled secondary antibody amplifies the signal. Food laboratories use it to confirm allergens like peanut or milk protein, to check trait expression in genetically modified crops, and to track how processing alters proteins — valued for its specificity when simpler tests leave doubt.