Multi layer chromatography of nucleic acids

摘要

Methods using two to (n) purification columns to separate full length 5′-DMT-on oligonucleotides with size ranging from 40 to 180-mers from short length 5′-DMT-on oligonucleotides. Two of the said methods require using some columns sequentially with the collection and reprocessing of an intermediate fraction and are used for oligonucleotides with length ranging from 70 to 180-mers. A third method is carried out with columns stacked and used in series and is best used to purify oligonucleotides with length ranging from 40 to 80-mers. In the presence of a high ionic strength buffer, the short length DMT-on oligonucleotides bind to the top stacked columns while the less hydrophobic contaminant or DMT-off failures do not bind and/or are being washed off. In a stacked configuration, the full length DMT-on oligonucleotides are retained by the bottom column while in a 15 sequential configuration, full length DMT-on oligonucleotides are collected and reprocessed.