Antibodies are the most commonly used tools in biological research. They are used in various applications such as Western Blot (WB), Immunoprecipitation (IP), Immunofluorescence (IF), Immunohistochemistry (IHC) and enzyme-linked immunosorbent assays (ELISA). Two of the most common hosts for producing research antibodies are rabbits and mice, but what are the differences between rabbit and mouse antibodies? Which antibody would be best suited for your research?
Rabbits, as a host, have a high success rate with a larger range of antigens compared to mice. In mice, antigens like small molecules and peptides are often non-immunogenic, while rabbits will produce the desired antibodies against challenging antigens including small molecules, peptides, and post-translational modification (PTM) sites. The resulting rabbit antiserum will consist of a larger variety of antibodies compared to mice antiserum.
In addition, the antibodies produced in rabbits usually recognize more epitopes per protein antigen than mouse antibodies since there is less immunodominance in rabbit.
In general, rabbit antibodies have a better affinity and specificity than mouse antibodies. Rabbit antibodies are highly specific antibodies that can bind to proteins in the picomolar range, while mouse antibodies recognize proteins to the nanomolar range with medium/high specificity.
Antibodies produced in mice are usually suitable for common applications such as WB, ELISA, flow cytometry, and IP. However, they are less likely to produce satisfying results for staining applications such as immunohistochemistry (IHC) and immunocytochemistry (ICC). In comparison, rabbit antibodies perform better in these assays, especially when used on mouse tissue samples.
Mouse antibodies require a shorter immunization period due to the size of the host. Usually, mice require one and a half months of immunization and rabbits require two to three months.
It is currently believed that rabbits have a completely different B-cell repertoire developmental mechanism than other mammals. The current model believes that there are three main steps in the development of rabbit B lymphocytes.
Neonatal B-cell repertoire
This library develops through the cell proliferation of B lymphocytes (B lymphopoiesis) in the liver and omentum of the embryo. The process commonly begins during the second to third week of pregnancy and is transferred to the bone marrow at birth.
Primary B-cell repertoire
The B lymphocyte pool continues to develop after birth in the bone marrow. During the two months after birth, the development process is transferred to the gut-associated lymphoid tissue (GALT) to form a primary B lymphocyte bank (also known as pre-immune B lymphocyte pool).
Secondary B-cell repertoire
After stimulation by exogenous antigenic substances, primary B lymphocytes further mature to form a secondary B lymphocyte pool (also known as immunized B lymphocyte library). In the bone marrow of adult rabbits, not many new B lymphocytes proliferate. Interestingly however, B lymphocytes containing the germline IgG gene were found in the spleen cells of adult rabbits. In addition, in rabbit homologous experiments, it was found that B cells from different rabbits can be transplanted into the stem cell niche of other homologous species. These findings demonstrate the longevity of rabbit B lymphocytes and their potential for self-renewal, thereby supporting the production of antibody repertoire throughout the life cycle of rabbits.
Due to the higher specificity, affinity, and broader applications, rabbit antibodies are generally priced higher than mouse antibodies.
In conclusion, rabbits produce superior antibodies compared to mice. However, customized rabbit antibodies projects also take longer and requires larger funding. The most suitable host for producing the best antibody for your research would depend on time, budget, and the application.