Editing Protein engineering (section)

====Chemical mutagenesis====
Chemical mutagenesis involves the use of chemical agents to introduce mutations into genetic sequences. Examples of chemical mutagens follow.

Sodium bisulfate is effective at mutating G/C rich genomic sequences. This is because sodium bisulfate catalyses deamination of unmethylated cytosine to uracil.<ref name=PoluriBook/>{{page needed|date=May 2017}}

Ethyl methane sulfonate alkylates guanidine residues. This alteration causes errors during DNA replication.<ref name=PoluriBook/>{{page needed|date=May 2017}}

Nitrous acid causes transversion by de-amination of adenine and cytosine.<ref name=PoluriBook/>{{page needed|date=May 2017}}

The dual approach to random chemical mutagenesis is an iterative two step process. First it involves the ''in vivo'' chemical mutagenesis of the gene of interest via EMS. Next, the treated gene is isolated and cloning into an untreated expression vector in order to prevent mutations in the plasmid backbone.<ref name=PoluriBook/>{{page needed|date=May 2017}} This technique preserves the plasmids genetic properties.<ref name=PoluriBook/>{{page needed|date=May 2017}}