Robust and precise chromatographic analytical methods are key for efficient development of mRNA production process. Three different analytical methods, which utilize three different column chemistries, are embedded in a ready-to-use PATfix™ mRNA analytical platform to support mRNA process development and product quantification and characterization.
Affinity-based chromatographic isolation of mRNA is robust and simple, lending itself as a useful industrial platform. mRNA constructs contain a 3’ polyA tail to increase stability in vivo, thereby affording the possibility of affinity purification using oligo-deoxythymidinic acid (Oligo dT) probes covalently coupled to a solid support. Poly-adenylated mRNA forms a stable hybrid with Oligo dT under high-salt conditions which is destabilized when the salt is removed, allowing mRNA to be released.
Due to an increasing productivity of IVT reaction, finding conditions that increase binding capacity of Oligo dT has been an intense focus of development. Multi-parallel approaches, such as screening in 96-well plate format, can significantly cut the development time by screening multiple conditions at once. 96-well plates can then be scaled-up to preparative scale, such as CIMmultus™ product line operated by chromatographic skids.
Optimized analytical methods are key components of a well-functioning analytical system, while method development usually comes with a time-consuming learning curve and optimization.
PATfix pDNA analytics platform, designed for in-process control of linear pDNA production, enables monitoring of pDNA linearization progression, as shown in Figure 1. Fully optimized and validated analytical methods, as well as guidelines for buffer and sample preparation come as part of the HPLC system, allowing users to focus on their specific application. In addition, the PATfix pDNA analytical package includes a pDNA calibration standard, which enables accurate quantification of the pDNA species of interest.
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.
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.