Site-directed or oligonucleotide-directed mutagenesis is a key method in the study of protein structure/function and gene expression control. If the nucleotide sequence of the gene is known, an oligonucleotide can be manufactured to introduce a single base change in the codon corresponding to the specific amino acid to be altered. The oligonucleotide is then used to generate a set of clones that can be identified and propagated. Learn More.