The use of combinatorial chemistry is fundamentally changing the pace
and scope of basic research and drug discovery. Since the introduction
of synthetic peptide libraries several years ago, combinatorial chemi
stry has proven to be a powerful tool for the generation of immense mo
lecular diversities of peptides, peptidomimetics and new organic compo
unds. This article briefly reviews methods for the generation and appl
ication of combinatorial libraries, with particular emphasis on solubl
e synthetic combinatorial libraries. The utility of these molecular di
versities for basic research and drug discovery has been demonstrated
through the identification of numerous highly active compounds such as
antigenic peptides, receptor ligands, antimicrobial compounds and enz
yme inhibitors.