Preparing Protein Antigens from Sodium Dodecyl Sulfate-Polyacrylamide Gels for Immunization

Some native proteins can be isolated in pure form from cell lysates or tissue preparation using SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Antigens purified this way often induce good antibody responses. There are many different ways to process a gel fragment containing the protein of interest for injection. Such samples can be processed into small pieces and then injected, either by fragmenting the gel by passing it repeatedly through a syringe, or drying the entire gel slice and grinding it into a powder. Injections using the whole gel fragment should only be used with larger animals such as rabbits. For mice or other small animals, electroelution or electrophoretic transfer of the protein should be used to prepare the protein for injection. In the latter method, the protein is transferred to a suitable membrane, such as nitrocellulose or PVDF. The location of the desired protein is identified by staining, and the protein band is then cut from the surrounding membrane, minced, and dissolved in a small amount of dimethyl sulfoxide before subcutaneous injection into the animal.