Sdm changes the nucleotide sequence of the cloned gene at a specific site, which changes the amino acid sequence of the gene product. Can study the altered protein in vitro. Can put the mutated gene back into bacteria and study it in vivo (if it"s a bacterial protein) Extremely powerful approach to studying protein structure and function. Insert synthetic dna containing mutation in recombinant vector. Denature and anneal oligonucleotide primers with mutation. Use dna polymerase to extend and incorporate the mutagenic primers. Polymerization to extend primers using the two complementary template strands. Digest non mutated parental dna template with methylation-specific nuclease. Polymerization cycle is repeated many times - after a round or 2 the newly synthesized strands with the mutation become the template strands. Pcr amplifies (i. e. , makes millions of copies of) specific dna sequences in vitro. Extremely fast, extremely sensitive - requires very little template dna requires knowledge of partial nucleotide sequences.
