Codon usage plays a crucial role when recombinant proteins are expressed in different organisms. This is especially the case if the codon usage frequency of the organism of origin and the target host organism differ significantly. Therefore, to enhance efficient gene expression it is of great importance to identify rare codons in any given DNA sequence and subsequently mutate these to codons which are more frequently used in the expression host. Rare Codon Analysis Tool is powerful for codon usage frequency of your sequence and codon usage distribution. It can help you decide if your sequence needs to be optimized for heterologous gene expression.

NOTE: CAI(codon adaptation index) result from this tool is only for evaluation. It will not necessarily be the same as the one in our optimization report, since we might use different codon bias table for gene optimization.

Codon Usage is only one of many DNA sequence features that influence protein expression levels

codon optimization improves the efficiency of protein expression; codon optimisation considers many factors in addition to codon usage bias

You can choose a precalculated codon frequency table from the list (E. Coli, Yeast, Insect, or Mammalian).

Please choose the origin organism.

Please only paste in sequence data, and do not include sequence title and coordinates, but could include numbers; please only use letters A, C, G, and T.