Construction and evaluation of an instrument for the automated synthesis of oligodeoxyribonucleotides

The details for constructing an easily used and maintained laboratory instrument capable of routine oligodeoxyribonucleotide synthesis are presented. The synthesizer consists of relatively inexpensive, commercially available components and is controlled by an Apple IIe computer. Since reagents are distributed from pressurized reservoirs through a liquid manifold by opening solenoid-activated valves, no pump is required. More than 600 oligomers containing up to 122 bases have been produced with a condensation cycle time of approximately 15 min with apparent coupling yields of 98.5%. A unique bidirectional flow reactor and controlled reagent distribution system provide for rapid mass transfer during solvent and reactant equilibrations and for long-term stability of reagent solutions. Aspects of the system should also find use in other solid-phase synthetic and analytical strategies.