Christie D Mccollum

Fast oligonucleotide deprotection phosphoramidite chemistry for DNA synthesis

Abstract A new set of base protecting groups for cyanoethylphosphoramidite nucleosides and supports has been developed which decreases the post-synthesis time requirements. The traditional purine amide protecting groups, which require 8-16 hours at 55°C for deprotection in ammonia, have been replaced with the dimethylformamidine group. Oligonucleotides made with the new reagents require only 1 hour at 55°C or 8 hours at room temperature for complete deprotection. Dialkylformamidine phosphoramidites exhibit enhanced resistance to depurination compared to the traditional, or even the phenoxyacetyl, phosphoramidites.

An optimized polystyrene support for rapid, efficient oligonucleotide synthesis

Abstract An optimized type of polystyrene has been developed as a solid support for automated oligonucleotide synthesis. The non-swelling, rigid beads possess the attractive features of rapid reaction kinetics, efficient washing with organic solvents, and mechanical stability. Pore size, particle size, and polymerization formula and conditions have been optimized. The support material is derivatized to give primary amino functionality, which is near quantitatively coupled to 3′ p-nitrophenyl succinate nucleosides. Loading of the nucleosides can be precisely controlled in a range of 5 to 70 μmole per gram. The high yield synthesis of oligonucleotides, by phosphoramidite chemistry has been demonstrated up to 120 bases in length. Side reactions, such as extraneous chain growth, are minimized due to the lack of reactive functionality on the new support surface.

A New Support For Automated Oligonucleotide Synthesis

Abstract A particular form of polystyrene has been developed as a solid support for automated oligonucleotide synthesis. Extraneous chain growth is minimized due to the lack of reactive functionality on the new support surface. Therefore, it is well suited to small scale (50 nanomole) synthesis.