Assessment of Significance of Novel Proteins in Breast Cancer Using Tissue Microarray Technology

The arraying of formalin-fixed paraffin-embedded (FFPE) tissue, or less commonly frozen tissue, in tissue microarrays (TMAs) is an invaluable method with which to assess the association of novel proteins with a myriad of diseases in large cohorts of patients allowing high throughput evaluation as potential biomarkers. TMAs are most frequently used in cancer studies although they are not limited to this application. The most common method of evaluation of TMAs is via immunohistochemistry (IHC) which is an antibody-based protein localisation method routinely used in the clinical laboratory. However, significant issues still exist with respect to the validation of antibodies for use on TMA sections, with a large number of published studies failing to do so correctly [O'Hurley et al. Mol Oncol, doi:10.1016/j.molonc.2014.03.008, 2014]. Here, we present a method to determine the antibody specificity for use in immunohistochemistry (IHC), as well as the analysis and interpretation of results from an IHC-stained TMA.