Perspectives in 2003

More than 100 functionally distinct populations of lymphocytes can be identified in the peripheral blood of humans; each of these cell types undoubtedly has a unique role in the organization and effectiveness of an immune response. To distinguish specifically among these cells, however, it is necessary to measure simultaneously at least six to eight different T-cell surface antigens; additional functional correlations require even greater detection capability. For this purpose, flow cytometers capable of independently detecting as many as 12 different molecules now exist. Here we review the history and applications of this technology and discuss future directions.

The conceptual and technical approaches that led to the explosive growth of combinatorial chemistry began approximately 20 years ago. In the past decade, combinatorial chemistry has continued to expand with new chemistries, technological improvements and, most importantly, a clear demonstration of its utility in the identification of active compounds for research and drug-discovery programs. This article describes the conceptual and practical breakthroughs that have been critical for the development of synthetic combinatorial methods and includes the most recent developments and applications of mixture-based combinatorial libraries.