Overcoming Backpressure Problems during Solid-Phase Synthesis of Oligonucleotides

Abstract

During solid-phase synthesis of oligonucleotides in packed-bed reactors a substantial pressure build-up is observed during acid deprotection and subsequent solvent washing as the length of the support-bound oligonucleotide increases. Maintaining high flow rates of reagents and wash solvents is crucial to achieving the necessary short acid-exposure times during these steps. Exceeding the maximum system pressure limit, especially likely to occur in the latter part of the synthesis, may lead to shutdown of the automated synthesis. Addition of inert filling materials (e.g., glass microspheres, quartz sand) to the polymeric polystyrene-based solid support reduces pressure build-up, allowing automated synthesis to go to completion without reducing flow rates or manual intervention.