Immunizing Mice and Rats with Nitrocellulose-Bound Antigen

Immunizing Animals

The traditional method for generating polyclonal and monoclonal antibodies requires the immunization of an animal. Selecting the best species of animal and getting that animal's immune system to respond to a target antigen with an antibody response are essential to obtaining good-quality antibodies and hybridomas. There are only a limited number of opportunities for a researcher to intervene to manipulate and tailor the response to a particular antigen. Here we present advice and methods for designing the way in which the antigen is presented to the immune system (i.e., the immunization protocol), including the choice of animal, the antigen dose, the use of adjuvants, the route and number of injections, and the period between injections.

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.