A purification of synthetic oligonucleotides by using CIM™ monolith was evaluated. In this case study, the CIM™ anion exchange column had the capability to resolve oligonucleotides with small difference in comparative chain length.
A crude reaction mixture of synthetic oligonucleotide was loaded onto the CIM™ anion exchange column. Sample elution was achieved by salt concentration gradient. In comparison with conventional media, CIM™ monolith indicated higher resolution for major impurities.
Advantages of the characteristic properties of the CIM™ monolith were evaluated based on the high throughput purification of oligonucleotides under the identified gradient separation conditions. Over 99 % HPLC purity for the target oligoDNA was achieved by one-step purification from the crude reaction mixture.
Pre-activated CIMmic™ monolithic columns are cost efficient tools for screening of immobilisation conditions and small scale proof-of-concept testing of custom affinity columns and enzymatic reactors. Each column is assembled from a dedicated housing and discs containing a chromatography medium. With a bed volume of 100 μL, sample requirements are minimal, while inserting multiple discs in the housing adapts the column volume to application requirements. Different surface modifications of the discs enable immobilisation of a wide variety of ligands.
The increasing demand for messenger RNA (mRNA) as a therapeutic product requires larger production scales, and in turn more efficient extraction techniques. One of the most convenient techniques for its extraction is the use of oligo deoxythymidine (dT) coupled to a solid support . Oligo dT hybridises to the poly-adenylated tail which is present on most eukaryotic mRNAs, or synthetised onto the molecule during IVT, while other contaminant impurities (proteins, unreacted nucleotides, plasmid DNA, CAP analogues, partial transcripts, dsRNA side products and enzymes) lack the poly-A moiety and do not adhere to the solid support.
The increasing demand for messenger RNA (mRNA) as therapeutic product requires larger production scales, and in turn more efficient extraction techniques. Messenger RNA can be produced by in vitro transcription reactions (IVT) or isolated from eukaryotic cells. One of the most convenient techniques for its extraction is the use of oligo deoxythymine (dT) coupled to a solid support. Oligo dT hybridises to the poly-adenylated tail which is present on most eukaryotic mRNAs, or synthetised onto the molecule during IVT. Contaminant impurities, such as proteins, unreacted nucleotides, plasmid DNA, CAP analogues, partial transcripts, dsRNA side products and enzymes lack the poly-A moiety and are not retained on the solid support.
Chromatography using a solid phase consisting of large channels, such as monoliths, allows high flow rates and low shear forces. This can have a positive impact on recovery and productivity in purification of biologics. In addition, chromatography offers a closed system to minimise the risk of cross-contamination or exposure to RNase degradation, and an easily scalable platform.
CIMmultus™ Oligo dT is a chromatography column with Oligo dT ligands covalently bound on its surface. The sample containing poly-adenylated mRNA is loaded onto the column in a high salt concentration buffer. Salt ions screen the electrostatic repulsion between the negatively charged backbones and allow interaction between the Oligo dT and poly-adenylated tail of mRNA. Before product elution, a wash step at reduced salt concentration removes unspecifically bound contaminants. Elution of messenger RNA occurs under mild conditions in low conductivity buffer at neutral pH. In the absence of salt, electrostatic repulsion between the negatively charged backbones of Oligo dT and poly-adenine destabilises the T–A pairs and releases mRNA from the column.
Sample displacement chromatography exploits the different relative binding affinities of components in a sample mixture to achieve accummulation of a desired substance on the column before elution. In pharmaceutical applications, requirements for purity and efficacy of plasmid DNA (pDNA) as a therapeutic product are stringent. The separation of linear, supercoiled (sc) and open-circular (oc) pDNA isoforms has already been established on CIM® butyl (C4 HLD) monolithic columns at preprative scale. This process requires high concentration of ammonium sulphate for loading which increases the overall production requirements. Competing adsorption in sample displacement chromatography utilises the binding capacity of the chromatographic resin more efficiently and increases productivity of the chromatographic step.
This application note investigates three monolithic chromatographic supports with different hydrophobicities regarding their applicability for sample displacement of pDNA. CIMac™ C4 HLD (butyl, high ligand density) as a commercial product and pyridine and histamine as custom immobilised columns are compared.
Plasmid DNA (pDNA) as a pharmaceutical product has stringent requirements of purity and efficacy and often one or more chromatographic steps are used in the downstream process. High ligand density butyl-modified chromatographic monolith (CIMmultus™ C4 HLD, part of CIMmultus™ HiP² Plasmid Process Pack™ 1-1, product number 100.0011-2) is currently used in a polishing step of a pDNA purification process (1), is mainly used for separation of supercoiled (sc) pDNA separation from open circular (oc) and linear pDNA isoforms as well as for removal of remaining gDNA and RNA.
This application note presents a comparison of two different polishing processes employing monoliths, namely bind-elute (BE) and the more recently described (2) sample displacement purification (SDP).
DNA immunization can potentially induce both, humoral and cellular immune responses, and thus comprises an attractive approach for the development of an effective vaccine against HCV. The pIDKE2 plasmid is the main component of the CIGB's candidate vaccine against Hepatitis C virus (HVC), which is being used in HCV chronically-infected individuals during clinical trials phase 1 and 2.
In order to satisfy the high demanding plasmids consumption for clinical trials, the downstream process was improved to reach the quantities need it for clinical trials.
As the demand for plasmid DNA (pDNA) based gene therapy and vaccines increases, large scale, cost effective, and reproducible pDNA production will be required. The key to success is a real time in-process control method that ensures a high percentage of supercoiled pDNA in the final product. CIMac™ pDNA Analytical Column allows the monitoring of degradation products (open circular and linear pDNA), the removal of impurities (RNA), and ensures that each production step is yielding the amount of supercoiled pDNA anticipated.
A mixture of 8mer, 10mer, 12mer, 14mer, 15mer and 16mer Oligodeoxynucleotides was loaded on CIM® DEAE Disk and eluted in linear gradient mode at a flow rate of 6 mL/min (17 CV/min). Separation of all nucleotides could be accomplished within 60 seconds.