New molecular approaches to tissue analysis

The completion of the Human Genome Project will produce new opportunities for analysis of genes and their products in human tissue. The emergence of new technologies will enable investigators to directly examine human tissues for gene deletion, transposition, and amplification. In addition, we will be able to assess the complete gene expression of a tissue by examining the mRNA species using microarray chips. The emerging technologies of laser capture microdissection and RNA amplification enables these procedures to be carried out on groups of a few hundred cells, which will facilitate the examination of heterogeneous lesions. Finally, the application of tissue arrays and the capability of obtaining protein sequences in samples of only a few femtomoles of protein using desorption mass spectroscopy will revolutionize the analysis of protein expression.