Detection of IgE- and IgG-binding proteins after electrophoretic transfer from polyacrylamide gels

An electrophoretic technique for transferring proteins to a nitrocellulose membrane has been applied to proteins separated in polyacrylamide gels by isoelectric focusing, and gradient, SDS and 2-dimensional electrophoresis. Allergenic proteins were then identified by successive incubation of the transfer membrane with serum from allergic individuals and with 125I-labelled anti-human IgE, followed by autoradiography. Alternatively, IgG binding proteins were detected using 125I-labelled protein A. The application of these methods was illustrated with cereal grain proteins and sera from individuals with bakers' asthma and coeliac disease. This approach allowed the easy comparison of allergens important for different patients in a single source, and of allergens present in different but cross-reacting sources.