Protein Eng Des Sel. 2004 Sep;17(9):699-707. Epub 2004 Nov 2.

Bertschinger J, Neri D.

Covalent DNA display as a novel tool for directed evolution of proteins in vitro.

A methyl transferase fusion protein which binds covalently 5-fluorodesoxycytosine, gets linked to the constructs in which it is encoded.