When second best is good enough: Another probabilistic look at saturation mutagenesis

Research output: Contribution to journalArticlepeer-review


We developed new criteria for determining the library size in a saturation mutagenesis experiment. When the number of all possible distinct variants is large, any of the top-performing variants (e.g., any of the top three) is likely to meet the design requirements, so the probability that the library contains at least one of them is a sensible criterion for determining the library size. By using a criterion of this type, one may significantly reduce the library size and thus save costs and labor while minimally compromising the quality of the best variant discovered. We present the probabilistic tools underlying these criteria and use them to compare the efficiencies of four randomization schemes: NNN, which uses all 64 codons; NNB, which uses 48 codons; NNK, which uses 32 codons; and MAX, which assigns equal probabilities to each of the 20 amino acids. MAX was found to be the most efficient randomization scheme and NNN the least efficient. TopLib, a computer program for carrying out the related calculations, is available through a user-friendly Web server.

Original languageEnglish
Pages (from-to)258-262
Number of pages5
JournalApplied and Environmental Microbiology
Issue number1
StatePublished - Jan 2012

ASJC Scopus subject areas

  • Applied Microbiology and Biotechnology
  • Food Science
  • Biotechnology
  • Ecology


Dive into the research topics of 'When second best is good enough: Another probabilistic look at saturation mutagenesis'. Together they form a unique fingerprint.

Cite this