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.

While randomers are often used in protein mutagenesis procedures, they have several short comings. First, it is very difficult to achieve a truly random mixture. The second and more problematic issue is the inevitable introduction of stop codons. Fortunately, the ability to direct combinatorial mutagenesis using randomized oligonucleotides has been advanced by the use of trimer oligonucleotides. Read More.