[Interaction of short oligonucleotides derivatives with nucleic acids. VI. Discrimination of mismatch-containing complexes upon ligation of a short oligonucleotide tandem on DNA template].

The high ligation specificity of a tetranucleotide with a pair of flanking octanucleotides on DNA template by the action of T4 phage DNA ligase is shown. In a tetranucleotide-DNA template complex containing a mismatch, almost no ligation products are formed. The ligation of a tandem octanucleotide-tetranucleotide-octanucleotide makes it possible to identify accurately any single nucleotide substitution in a tetranucleotide binding site.