Directed evolution, the application of evolutionary design to enzyme engineering, requires effective screening strategies to isolate those proteins that perform a desired function from the libraries generated by the techniques. In Directed Enzyme Evolution: Screening and Selection Methods, seasoned practitioners from many leading laboratories describe their leading and readily reproducible screening strategies for isolating useful clones. These techniques have been optimized for sensitivity, high throughput, and robustness, and are of proven utility for directed evolution purposes. The assays presented use a variety of techniques, including genetic complementation, microtiter plates, solid-phase screens with colorimetric substrates, and flow cytometric screens. There are also representative examples of how phage libraries may be interrogated for enzymatic activity. Each protocol contains detailed step-by-step instructions and many notes on how best to deal with the problems that may occur. An accompanying volume, Directed Evolution Library Creation: Methods and Protocols (ISBN 1-58829-285-1), describes readily reproducible methods for the creation of mutated DNA molecules and DNA libraries.
Taken together, Directed Enzyme Evolution: Screening and Selection Methods and Directed Evolution Library Creation: Methods and Protocols capture for newcomers and more experienced investigators alike all the key methods for using directed protein evolution to better understand protein structure-function relationships, to discover new enzymes and therapeutic proteins, and to design new assays suitable for specific applications.