Improved Conditions for Solid Phase Synthesis of Oligonucleotides on PS-PEG Copolymers

Polystyrene-polyethylene glycol (PS-PEG) tentacle polymers with loadings of up to 60/<mol/g were used for standard oligonucleotide synthesis. As these resins are easy to handle and stable under reaction and cleavage conditions they may be used alternatively to con­ trolled pore glass (CPG) as the most commonly used solid support for oligonucleotide syn­ thesis. However, structural and chemical properties of the PS-PEG resins require modified conditions to guarantee syntheses with high coupling efficiencies. Oligonucleotides (O D N ) of various sequences and lengths have successfully been synthesized using HPLC and capillary electrophoresis (CE) for purity control. Additionally, electrospray mass spectrometry (ES-MS) was used for product identification.