Gene Libraries

SeSaM-Biotech offers mutant gene libraries generated by our proprietary mutagenesis technologies.

Just provide the gene of interest or it’s sequence and select a library suiting your needs.


  • SeSaM (Sequence Saturation Mutagenesis)
  • epPCR (error-prone PCR)

SeSaM, the abbreviation of Sequence Saturation Mutagenesis, is a patented method to create diversity on the gene level far higher than the diversity generated by conventional methods such as error-prone PCR.

Why is SeSaM the ideal random mutagenesis method?

  • SeSaM targets every single protein position equally
  • SeSaM exchanges an amino acid by all the other 19 amino acids with a probability above 0.9
  • SeSaM has a built-in recombination option
  • SeSaM libraries have reduced hotspots that leads to decrease in screening needs
  • SeSaM allows tuning of the Ts/Tv-ratio

Our technologies are not restricted by gene length. We can vary the mutational load from 1 mutation/1000 bp up to more than 30 mutations/1000 bp.


  • SDM (Site Directed Mutagenesis)
  • SSM (Site Saturation Mutagenesis)
  • OmniChange (Multi-Site Saturation Mutagenesis)

Our focused mutagenesis technologies allow us to insert any desired mutation into the gene sequence of interest. With OmniChange, up to 5 Codons may be saturated simultaneously and is useful by structure-guided generation of combinatorial libraries.

See also our computational section for more information.


  • OmniChange (Multi-Site Saturation Mutagenesis)
  • GeneShuffling (for Domain Engineering)
  • PTRec (Chimaeragenesis after GeneShuffling)
  • Casting-epPCR

Be it on the codon-level or on domain-level of the amino acid structure of the protein, our technologies offer full flexibility in the generation of combinatorial libraries. Upon request, we can support the mutagenesis by computational simulations and docking analysis.

See also our computational section for more information.

After diversity is generated on the gene level, the library is cloned in high-copy plasmids specificially designed to achieve high transformation efficiencies. Restriction enzyme and Ligase-free cloning techniques are available. Cloning and transformation in customer provided vectors and strains is also possible.


Please contact us to receive a detailed quotation tailored to your needs.

Gene Libraries as part of the QuESt-service


Gene library generation is an essential part of any Directed Enzyme Evolution project carried out at SeSaM-Biotech and therefore automatically included in the QuESt-service.

Available expression systems comprise Escherichia coli, Bacillus subtilis, Corynebacterium, Saccharomyces cerevisiae and Pichia pastoris, each proprietary strains optimized for sufficiently high transformation efficiency and reliable enzyme expression to make the most out of any Gene Library.


Learn more about our all-in-one Directed Evolution service QuESt here or get in touch with us.