UNIT 24.6 Directed Evolution of Proteins In Vitro Using Compartmentalization in Emulsions

  1. Eric A. Davidson1,
  2. Paulina J. Dlugosz1,
  3. Matthew Levy2,
  4. Andrew D. Ellington1

Published Online: 1 JUL 2009

DOI: 10.1002/0471142727.mb2406s87

Current Protocols in Molecular Biology

Current Protocols in Molecular Biology

How to Cite

Davidson, E. A., Dlugosz, P. J., Levy, M. and Ellington, A. D. 2009. Directed Evolution of Proteins In Vitro Using Compartmentalization in Emulsions. Current Protocols in Molecular Biology. 87:24.6:24.6.1–24.6.12.

Author Information

  1. 1

    University of Texas at Austin, Austin, Texas

  2. 2

    Albert Einstein College of Medicine, Bronx, New York

Publication History

  1. Published Online: 1 JUL 2009
  2. Published Print: JUL 2009


This unit describes a protocol for the directed evolution of proteins utilizing in vitro compartmentalization. This method uses a large number of independent in vitro transcription and translation (IVTT) reactions in water droplets suspended in an oil emulsion to enable selection of proteins that bind a target molecule. Protein variants that bind the target also bind to and allow recovery of the genes that encoded them. This protocol serves as a basis for carrying out selections in emulsions, and can potentially be modified to select for other functionalities, including catalysis. This selection method is advantageous compared to alternative selection protocols due to the ability to screen through very large-size libraries and the ability to express and screen or select for functions that would otherwise be toxic or inaccessible to in vivo selections and screens. Curr. Protoc. Mol. Biol. 87:24.6.1-24.6.12. © 2009 by John Wiley & Sons, Inc.


  • directed evolution;
  • in vitro compartmentalization;
  • emulsion