Screening and selection methods for large-scale analysis of protein function.

High-throughput assays hold tremendous promise for protein engineering and proteomics. With powerful assays it should be possible to evolve, for example, a stereoselective esterase for the chemical synthesis or a site-specific endonuclease for biomedical research. Entire cDNA libraries, which encode all of the proteins expressed in a given organism or cell line, should simply be passed through a battery of biochemical assays to determine the function of each individual protein. Herein we look at the types of assays that have been developed and how close we are to our goals of engineering proteins with new activities as well as rapidly assigning function to the thousands of proteins that make up each genome.