Automatic synthesis of oligodeoxynucleotides and mixed oligodeoxynucleotides using the phosphoamidite method.

A simplified procedure for making and using the deoxynucleoside phosphoamidites (1 a-d) in the automated synthesis of oligodeoxynucleotides has been developed. The reagents prepared show good stability in solution. The reactivity of the reagents was found to be directly proportional to their concentrations, which makes it possible to synthesize mixed oligomers in desired ratios. Oligomers up to 45-mer have been synthesized using a coupling cycle of twenty min.