Notes: Saccharin 1-methylimidazole is a chemical activator that has been commonly used in solid-phase synthesis of DNA and RNA oligonucleotides.{46594} It catalyzes the phosphoramidite coupling reaction of the 5' hydroxy of immobilized nucleosides and the amine group of nucleoside phosphoramidite. Saccharin 1-methylimidazole has been used to synthesize single-stranded DNA (ssDNA) oligonucleotides that are resistant to nuclease digestion.{46595}