Evaluation of antibody crossreactivity in mouse tissues: Study of a panel of antibodies reacting to human antigens

The increasing use of immunohistochemistry has led to the development of a great number of antibodies directed to human antigens. On the other hand, antibodies reacting to animal tissues, especially from murine origin, are sparse and seldom available from commercial sources, in this article we show the results of a study carried out in mouse tissues, testing a group of antibodies directed to human antigens commonly used in most laboratories for human pathology. Antibodies to cytokeratins, vimentin, desmin, actins, T cells, B cells, macrophages, and proliferation markers [Ki67, proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine (BrdU)] were employed using heat-induced epitope retrieval and several mouse tissues as targets. We found strong reactivity, with little or no background, for vimentin, both muscle actins, desmin, CD3, CD79a, PCNA, and BrdU. All the other antibodies tested were negative. The lack of reactivity of some antibodies on mouse tissues is in concordance with previous results in tissues from other animals and may reflect differences in antigen structure among species. On the other hand, our data show a group of antibodies, commonly used in histopathology laboratories, reacting to mouse tissues. This may allow researchers to apply immunohistochemical staining in the characterization of some cell populations in experiments using this laboratory animal.