Tissue microarrays: a current medical research tool.

Recent research in molecular biology has identified a significant number of novel markers, which may have diagnostic, prognostic and therapeutic significance. This is particularly pertinent in the field of cancer. Validation of these markers in multiple clinical specimens is currently performed by traditional histopathological techniques, which are disappointingly time consuming, labour intensive and, therefore, economically costly. These limitations have hampered the introduction of many novel markers into everyday clinical practice. The tissue microarray (TMA) is a high throughput technique, which allows the rapid and cost effective validation of novel markers in multiple pathological tissue specimens. Tissue from up to a 1000 histology blocks can be arrayed accurately onto a newly created paraffin block, at designated locations. Subsequently, morphological and molecular investigations can be performed to determine the clinical significance of the novel markers tested. It is now firmly established that the TMA can significantly accelerate the processing of a very large number of tissue specimens with excellent quality, good reliability and preservation of original tissue, with ultimate clinical benefit.