Chemical and photochemical ligation of oligonucleotide blocks

Several efficient means for joining oligonucleotides in dilute solution by non-natural internucleotide bridges are discussed. It is also shown that an oligonucleotide containing a -OP(O)(O-)S- link can function as an effective template in PCR amplification and that oligonucleotide probes containing stilbenedicarboxamide groups can serve in monitoring the presence of mismatched bases in an oligonucleotide target.