Design of synthetic oligonucleotide duplexes for site-directed mutagenesis with recombinant plasmids

Screening for site-mutated plasmids may be greatly facilitated by the different occurrence of the restriction sites distinguishing the altered sequence from the original one. Synthetic oligonucleotides can be so designed that they, apart from defining the mutation, also create a new restriction site recognizable in the restriction pattern of the mutant plasmid.