Oligonucleotide purification

Anion exchange chromatography (AIEX) is a commonly used method for purifying oligonucleotides. This method separates negatively charged oligonucleotides based on their length. The nucleic acid's negatively charged phosphate groups in the backbone bind to the resin via positively charged groups on the AIEX resin. The strength of the binding increases with the length of the target. To elute the adsorbed oligonucleotides, the salt concentration gradient is increased to release the oligonucleotides in the order of increasing length. AIEX is a cost-effective technique for purifying oligonucleotides that can provide high purity and yield in a single step. 

WorkBeads 40Q resin is a high-capacity, strong anion exchange resin derivatized with quaternary amine ligands. WorkBeads 40Q resin demonstrates the property of high-resolution separation while giving low backpressure to facilitate purification in bioprocess columns. The agarose-based resin is manufactured using a proprietary method that produces porous beads with a tight size distribution and exceptional mechanical stability. It will bind negatively charged substances and can be used over a broad pH range (3 – 13). WorkBeads 40Q is highly suitable for the purification of oligonucleotides, giving high purity and good yields.

Solid-phase synthesis of oligonucleotides generally yields material of relatively high purity. However, for many applications, and especially for therapeutics, purification is needed to remove incomplete or erroneous sequences. Purification is best achieved by combining several separation techniques. A common combination is hydrophobic interaction chromatography (HIC) followed by anion exchange chromatography. HIC is particularly useful for separating molecules according to differences in their surface hydrophobicity through a reversible interaction between the molecules and the hydrophobic surface of the HIC resin. 

WorkBeads 40 Butyl SH is a resin for hydrophobic interaction chromatography designed for research and industrial scale purification of proteins, peptides, plasmids, and oligonucleotides by utilizing the difference in their surface hydrophobicity. The functional ligand of WorkBeads 40 Butyl SH is n-butyl thioether. Since butyl is a very hydrophobic linear chain, minimal mixed-mode interactions are expected. The resin is optimized to offer reliable binding performance. The property of high-resolution separation, in combination with low backpressure, allows both capture and polishing purification applications in standard bioprocess columns.