ABSTRACT
Why use site-directed mutagenesis? Classically a great deal has been learned about gene function by analyzing mutations. Typically, the organism under study is exposed to a mutagen to generate random mutations and those mutants that show a particular phenotype are selected for further study. A range of methods, including DNA sequencing, are used to identify which gene(s) have been mutated and the nature of the changes. This gives valuable information on both gene and protein function. However, this classic approach is extremely laborious and involves screening large numbers of random mutations in the hope of finding useful mutations in the gene of interest. In contrast, recombinant DNA techniques allow defined changes to be made to the gene sequence and generate the desired mutations with certainty. These techniques are collectively called site-directed mutagenesis or in vitro mutagenesis.
