Custom-made gene mutant libraries

Gene mutant libraries


Gene mutant libraries are powerful tools for generating a protein with desired properties. As opposed to cDNA libraries of existing genes, randomized mutant gene libraries represent variants of a single gene. These variants are created by strategically randomizing individual nucleotides or codons. However, due to the degeneracy of the genetic code and the fact that some amino acids are encoded by more codons than others, a conventional library will overrepresent some amino acids as compared to others and will contain unwanted STOP codons within the gene.

PolyQuant’s technology for generating codon-precision libraries circumvents these obstacles. Using sets of codons for each randomized amino acid position, facilitates reducing the time and cost of screening significantly.


ordering workflow library


The maximal number of obtainable clones varies with the gene, vector and host cells, but is usually in the range of 107 to 109.


Library, based on 5 randomized amino acid positions.
When created based on conventional, single-nucleotide randomizations, it would require the production of significantly more clones than a codon-precision library.

NNS PolyQuant
Codons 32 20
Stop codons 1 0
Minimal # of codons/aa 1 1
Maximal # of codons/aa 3 1
Total number of variants for the library with 5 randomized codons
1.01 x 108 9.59 x 106


PolyQuant’s codon-precision libraries come royalty-free and PolyQuant does not claim any rights to products based on these libraries.