Tissue Arrays

Tissue microarrays, also called tissue arrays, consist of different types of representative biological tissue, cut in small pieces and adhered onto a solid support, such as a glass slide. These tissues are finely sliced, with a thickness between 2 to 5 micrometers and diameters that can range from 1 millimeter to 2 centimeters. Typically, a panel of tissues can be cataloged by disease, such as similar types of cancerous tissue from different patients. Others can consist of a variety of normal tissue from different organs within one species of animal, or similar tissue types across different species. A key advantage of the tissue array is the ability to simultaneously analyze a large number of specimens. Researchers can carry out higher throughput experiments for applications such as histological staining, immunohistochemistry, and in situ hybridization. The smaller area of tissues not only conserves precious tissue samples, but also working assay reagents, as well as time and cost. Some considerations in choosing a particular tissue array or tissue microarray, in addition to the research-specific application, include the tissue source, relevant disease, presence of controls, and number of specimens.