Site-Directed and Site-Saturation Mutagenesis Using Oligonucleotide Primers

A very powerful method of probing DNA-protein interactions is the technique of site-directed mutagenesis. Using this approach one can introduce specific amino acid changes at any given position in the amino acid sequence of a DNA-binding protein, and test the functional consequences of these mutations in vitro. Furthermore, it is also possible to investigate the resulting mutations in vivo if a suitable phenotypic change can be measured. If so, strategies that introduce random base changes to a given codon (or indeed to a larger region of the protein) are particularly valuable.