Non-specific binding of anti-human IgE peroxidase-linked conjugates to legume proteins in immunoblots

Non-specific binding was observed in immunoblotting of legume proteins with commercial anti-human IgE and IgG antibodies conjugated with peroxidase when incubations were conducted without prior incubation with human sera of legume-allergic individuals. The non-specific binding was encountered with ten legume species. It was not associated with endogenous peroxidase or the peanut or soybean lectins. The degree of non-specific binding diminished with roasted peanut extracts as compared to raw peanut extracts. The cause of this non-specific binding remains unknown, although it may be related to the animal source of the antiserum or the method of conjugation of the antibody with peroxidase. This interference in immunoblotting can be easily detected with controls lacking incubation with human sera.