Some of your applications may require oligos with the highest quality. Cristallography studies, tri-dimensional construction, difficult cloning or gene synthesis are among these demanding applications.
The quality of the synthesis, the deprotection efficiency and the purification level are the most critical points to consider in order to reach the highest purity grade.
The UltraPureGold™ purification has been developed to provide the best oligonucleotides from 8 to 140 bases long with an ultrahigh quality. This process relies on a proprietary synthesis and purification process combining a synthesis on polystyrene support, special amidites, optimized deprotection and dual purification. This latter step is adapted based on the length and, if necessary, on the structure of the oligonucleotide.
- Optimized synthesis: the polystyrene 3’-end support has been adopted for its high retention capacity and also for its resistance to high amidites excess and long coupling times. This support is as efficient for long oligonucleotides as for short ones. The selected amidites are ultrapure and offer an increase in the coupling efficiency. In order to optimize all reactions and washing steps, we have selected the acetonitrile as solvent.
- Improved deprotection: in order to provide a fully accessible oligonucleotide, without any protecting groups inactivating the final oligonucleotide product, we are applying a long, soft treatment allowing the optimal deprotection without damaging the sequence itself.
- Dual purification: The purification is mainly chosen depending on the length of the oligonucleotides.
For unmodified oligonucleotides up to 26 bases long, a dual HPLC provides the best quality to reach 95 % purity. For longer oligonucleotides between 26 and 140 bases, a specific purification process is applied.
Firstly, a Reverse-Phase cartridge purification eliminates most of the aborted sequences.
Secondly “long PAGE” purification separates precisely the full-length oligonucleotide from the remaining n-x by-products.
Finally, a gel filtration occurs to remove all the residual purification reagents. If required, an additional round of purification is performed in order to reach a purity level up to 85% for oligonucleotides between 26 and 59 bases long or 80 % purity for oligonucleotides longer than 60 bases.
- Quality Control: all UltraPureGold™ oligonucleotides are controlled in two stages. A first QC is performed after the purification to ensure that the synthesis was efficient enough to reach the expected purity level of the final product. Then, a Capillary Gel Electrophoresis (CGE) is realized as a second QC. The electrophoregrams are provided as an additional documentation.
This UltraPureGold™ process has been co-developed with some customers and validated for many stringent applications. These purification steps are demanding on the final yield, therefore we cannot guarantee large final amounts of oligonucleotides. This is the best process available on the market providing very high quality oligonucleotides for the most demanding applications.