Directed evolution (
DE) is a method used in
protein engineering that mimics the process of
natural selection to evolve
proteins or
nucleic acids toward a user-defined goal. It consists of subjecting a
gene to iterative rounds of mutagenesis (creating a library of variants), selection (expressing the variants and isolating members with the desired function), and amplification (generating a template for the next round). It can be performed
in vivo (in living cells), or
in vitro (free in solution or microdroplet). Directed evolution is used both for
protein engineering as an alternative to rationally designing modified proteins, as well as studies of fundamental
evolutionary principles in a controlled, laboratory environment.