Immunohistochemical staining (IHC), a technique using antibodies to detect specific molecules on cells, is an essential tool that pathologists use in diagnosing cancer. But as Brady scientist Angelo M. De Marzo, M.D., Ph.D., and colleagues recently discovered, there’s a huge variation in the quality of IHC tests available – and this could affect accuracy.

“IHC is used in thousands of research and clinical laboratories,” De Marzo says, “but there is widespread misunderstanding about the two classes of antibodies used in IHC staining: clinical grade and research grade. Clinical grade antibodies are validated for accuracy prior to their use in hospital pathology labs, but are limited in number,” with about 500 antibodies in use. “On the other hand, the majority of commercially available research-grade antibodies are not held to the same standards of validation, and there are now more than 3.8 million of these. Overall, we estimate that at least half of published studies using research IHC assays have potentially incorrect staining results due to lack of antibody validation.”

“A cornerstone of scientific research is the ability to reproduce findings of colleagues’ studies, to either affirm or reject them,” says Brady scientist Karen Sfanos, M.S., Ph.D., co-author of this study. “The problem with having many incorrect IHC results in the literature is that it makes it difficult to rely on prior results, which can significantly slow down research.”

This work was published in a special issue of the Asian Journal of Urology that was dedicated to the late Donald Coffey, Ph.D., longtime Director of the Brady Research Labs. In the publication, the Brady scientists provide numerous examples of validated assays, literature and other resources to help pathologists and scientists find the right IHC antibodies and assays. Other authors and contributors included Srinivasan Yegnasubramanian, William Nelson, Tamara Lotan, Ibrahim Kulac, Jessica Hicks, Qizhi Zheng, Charles Bieberich and Michael Haffner.