Tissue microarrays are a platform for high-throughput analysis of tissue specimens in research. They are used for target verification of results from complementary deoxyribonucleic acid (cDNA) microarrays, expression profiling of tumors and tissues, as well as in epidemiology-based investigations. Tissue microarrays are a simple reagent that can be constructed from archival paraffin-embedded tissue for immunohistochemical staining, in situ hybridization, and other methodologies. The design and precision in execution of a tissue microarray is essential to obtain the desired results. Tissue microarrays are a powerful proteomic platform for research.