Application of sample displacement techniques to the purification of synthetic oligonucleotides and nucleic acids: a mini-review with experimental results

Clinical development of antisense drugs is rapidly increasing requirements for large quantities of oligonucleotides. As part of the manufacturing process appropriately large scale separation techniques must be developed. This article reviews applications of sample self displacement techniques to the purification of oligonucleotides and nucleic acids, wherein sample components act as displacers and enhance purities. Applications for other solutes are also reviewed where similar methods may be of use in oligonucleotide purification. Experimental data is presented for sample self displacement anion-exchange chromatography of the clinically important phosphorothioate oligonucleotides. The technique can enhance full-length purity of the product and offers maximal utilization of the chromatographic media. Full-length purities of 95% and higher are achieved by this approach and recovery yields are up to 70% depending upon starting feed purity. Recycling and real time process monitoring can further improve recovery. Techniques for column saturation with multiple linked columns are presented and their applications to oligonucleotide purification are discussed. (C) 1998 Elsevier Science B.V.