Posters

mRNA has been at the forefront of both scientific and general public interests from the start of the COVID-19 pandemic. However, there are still limited options available for rapid characterization of mRNA containing samples. For precise characterization of an mRNA sample, first the presence and concentration of mRNA molecules in the sample needs to be identified. In the second step, any contaminants in the sample coming from the IVT reaction need to be identified and quantified. All major components of the IVT reaction; nucleotides, capping reagent, enzymes and DNA template may be present in the mRNA sample. In addition, impurities such as shorter, incomplete RNA fragments, and in particular, dsRNA may also be present. Contaminants may also come from the mRNA in vitro instability, caused by spontaneous hydrolyzation of the mRNA backbone. These issues can be mitigated using appropriate analytical tools throughout the mRNA production and purification steps.

Affinity-based chromatographic isolation of mRNA is robust and simple, lending itself as a useful industrial platform. mRNA constructs typically 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. Typical dynamic binding capacity (DBC) of CIMmultus Oligo dT for mRNA is 2-4 mg/mL; ever higher IVT productivity will require higher binding capacities. Screening experiments to elucidate factors affecting CIMmultus Oligo dT binding capacity for mRNA were performed in CIM® 96-well Oligo dT format. A simplified model identified NaCl, guanidine hydrochloride (Gu-HCl) and MgCl2 concentration as the key factors contributing to DBC. Buffer chemistry, buffer pH, salt type and mRNA concentration had little or no effect on DBC.

The cost of mRNA production is driven by IVT reagents, particularly the capping reagent. Optimization of mRNA yield is therefore crucial for lowering the cost of mRNA production. In order to monitor IVT reaction over time, we implemented a rapid at-line HPLC monitoring of consumption of NTPs with concomitant production of mRNA, with a sub-3 min read-out. Use of CIMac PrimaS analytical column allowed us to determine and adjust key IVT components that influence the kinetics of mRNA production and are critical for optimization of continuous addition of reagents, i.e. fed-batch IVT.

CIM® PrimaS column family combines multimodal anion exchange/hydrogen bonding properties, binding molecules with predominantly negative charge. It is used as capture method for purification of mRNA from IVT (in-vitro transcription) reaction mixture with high binding capacity. High salt wash is used to elute the plasmid and other IVT components from the column without affecting binding of ssRNA.

Microvolume spectrophotometers are commonly used as quick and easy method to measure concentration and purity of nucleic acids. DSP process for purification of mRNA includes unit operations with salt concentrations up to 2.75 M (HIC) or up to 1.25 M (Oligo dT) during load and low salt concentrations during elution.

mRNA has been at the forefront of both scientific and general public interests from the start of the COVID-19 pandemic. The demand for the mRNA product has been incredible for the last couple of years. However, there are still limited options available for a rapid mRNA quantification and characterization. In this work, mRNA analytics using a CIMac Oligo dT column is presented. mRNA is a specialized group of RNAs that carries the blueprints for building proteins from the cell’s DNA in the nucleus to the ribosomes in the cytoplasm. One of the features of mRNA molecules is a polyadenylated (poly(A)) tail on the 3’ end, that can be up to 250 nucleotides long. This feature enables mRNA to bind to the Oligo dT column. HPLC Oligo dT analytics provide a solution for fast and reproducible quantification of mRNA throughout all the process steps of mRNA production and purification. The presented method was validated using mFix4, an uncapped mRNA analog produced in-house, 3969 nt long molecule with a poly(A )tail length of 95 nucleotides.

Messenger RNA (mRNA) is becoming a major contributor in the fields of gene therapy and vaccines, including those developed in response to the COVID-19 pandemic. Convective Interaction Media® (CIM®) Styrene divinylbenzene (SDVB) monolithic columns are promising for high resolution purification and separation of mRNA, enabling large-scale production of this molecule. This study demonstrates the ability to prepare homogeneous SDVB monoliths with desired chromatographic properties and economical analytics over the whole size range.

Endotoxins are robust and persistent impurity, which are native to majority of phage substrates. Two anion exchangers, CIMmultus PrimaS and H-Bond, were tested for their capacity for endotoxin removal in comparison to well known strong anion exchanger, CIMmultus QA. 

The recently demonstrated efficacy of mRNA-based Covid-19 vaccines has shown promise of this therapeutic format, but also highlighted the need for higher efficiency of mRNA production to meet enormous needs for global vaccine supply.

Typical mRNA production process involves three key steps: 1) plasmid DNA (pDNA) production in supercoiled (sc) isoform, linearization and purification, 2) in-vitro transcription (IVT) reaction and 3) mRNA purification.

Here we present a chromatographic toolbox and mRNA IVT synthesis for integrated mRNA production from pDNA to mRNA purification, including in-process analytics. This high yield process reduces the overall number of purification steps required, improves recoveries, results in extra low protein impurity and allows for very efficient dsRNA removal.

The IVT reaction is one of the most expensive steps in mRNA production process and its optimization to reach high mRNA yield is of key importance Standard mRNA quantification techniques like absorbance and fluorescence based assays are time consuming and cannot be performed at line as the IVT reaction progresses In addition, other reaction components like nucleotides and pDNA interfere in the analytical results and reduce the method’s accuracy A new approach shown here uses CIMac PrimaS™ analytical HPLC column to separate and quantify several key IVT components with a very short run time, enabling fast “at line” tracking

Optimizing processing steps in sc pDNA isolation is critical for obtaining good process yields as well as high product purity. PATfix platform with convective chromatography media (e.g. monolith) offers a rapid analytical method to characterize complex biomolecular mixtures and gives immediate feedback during process development. E coli lysis represents such a challenging step, where multiple critical quality attributes need to be identified and critical processing parameters optimized. This approach leads to better yields and product purity, allowing for simplified downstream steps. A new PATfix analytical platform presented here uses CIMac pDNA column, to separate and characterize plasmid from impurities, allowing for easy optimization of key parameters such as RNA removal.

In mRNA production process, downstream purification of in vitro transcription (IVT) reaction often relies on precipitation methods which cannot provide resolution, recovery, or reproducibility to consistently produce a safe and effective product with good process economics. mRNA is a large biomolecule (mass of 1000 nt is ~ 150 kDa and >100 nm in diameter) for which porous particle chromatography lacks the ability to support high capacity and throughput to achieve good process economics. Convective flow chromatography media (e.g. monoliths) is an optimal platform for purification. A fully scalable chromatographic purification process is presented for a posttranscriptionally capped in vitro transcribedmRNA.

PATfix with convective chromatography media (e.g.monolith) offers a rapid analytical method to characterise complex mixtures. Transcription reaction used for production of mRNA represents such a mixture, with components varying in size, chemical and physical properties. A new analytical approach (PATfix) presented here uses CIMac PrimaS to separate IVT components such as triphosphate-nucleotides (NTPs), enzymes, DNA template and RNA in a very short gradient.

Linearised pDNA is currently the starting point of In-Vitro-Transcription processes to synthesize mRNA. Large scale purification protocols for manufacturing of pDNA used for Gene Therapy applications typically include two chromatography steps. The first step captures both linear, open circular and supercoiled pDNA species. The polishing step enriches supercoiled pDNA, while discarding other isoforms. We describe a single-step-capture strategy to maximize the recovery of pDNA for further linearization.

The increasing demand for messenger RNA (mRNA) as a therapeutic product requires larger production scales and more efficient extraction techniques. In this poster, fast and efficient way to purify poly-adenylated mRNA using affinity chromatography on CIMmultus™ Oligo dT column is presented.

The poly-adenylated tail of mRNA interacts with covalently bound oligo dT ligands in high-salt loading conditions, where electrostatic repulsion between negatively charged backbones of both, mRNA and oligo dT, are reduced and H-bonding in T-A base pair is emphasized. High salt concentration additionally screens out attractive electrostatic interactions between mRNA and other components in the process sample, thus facilitating aggregate reduction in purified product.

One of the handicaps of working with bacteriophages is the long duration required to perform plaque assays. Plaque assays also impose questions about accuracy and precision relative to the scale and experience of the persons performing and interpreting them. This poster presents a pair of high precision, high accuracy chromatography-based assays that permit determination of phage concentration in less than 1 hour. Sensitivity of UV absorbance is poor because of the low concentration of phages. However, phage sensitivity is strongly amplified by monitoring the chromatogram with either fluorescence or MALS. Fluorescence works by measuring the fluorescence emission from tryptophan residues of the phage proteins. MALS works by passing a laser beam through the sample and reading the scatter produced when it encounters a particle. Larger species generate more scatter.

Bacteriophages represent immense potential as therapeutic agents. Many of the most compelling applications of bacteriophages involve human therapy, some pertinent to gene therapy, others involving antibiotic replacement. In bacteriophage research and therapy, most applications ask for highly purified phage suspensions, as such it is crucial to reduce proteins, endotoxins, DNA and other contaminants. The most common technique for purification is ultracentrifugation using cesium chloride gradients. This technique is elaborate, cumbersome, expensive and difficult to scale-up.
Alternative techniques for purification are usually time consuming and affect phage recovery and/or viability. In this study we present efficient two-step chromatographic purification method with binding phages to a stationary phase - Convective Interaction Media (CIM®) monoliths. The aim of the study was to develop robust, fast and effective virus purification platform that can be used for several types of bacteriophages for any application. In this work bacterial lysate with bacteriophage T4 (host E.Coli) was used.

In recent years bacteriophages were identified as a useful potential tool for different applications such as alternative to antibiotics, detection of pathogenic bacteria, delivery vehicles for protein and DNA vaccines and as gene therapy delivery vehicles. For all listed fields of use it is important that phages are highly purified with preserved biological activity. Phage and other virus purification have traditionally been carried out by CsCl2 density gradient ultracentrifugation, which is however difficult to be scaled-up. An alternative is chromatography, which already proved to be efficient for separation and purification of certain virus types. Methacrylate monoliths (CIM Convective Interaction Media® monolithic columns) were designed for purification of bionanoparticles and they already proved to be very efficient for concentration and purification of several plant and human viruses (influenza A, influenza B, adenovirus type 5, hepatitis A and others).

Our aim was to investigate whether CIM methacrylate monolithic columns can be implemented for purification of phages. Staphylococcus aureus phage VDX-10 was selected. Chromatographic support chemistry and buffer screening led to development of purification method on strong anion exchanger. Optimised single step purification method developed for S. aureus VDX-10 phage on CIM® QA monolithic column resulted in efficient removal of host cell DNA and proteins with high recovery of viable phage.

Bacteriophages were in recent years identified as a useful potential tool for different biotechnological applications such as alternative to antibiotics, detection of pathogenic bacteria, delivery vehicles for protein and DNA vaccines and as gene therapy delivery vehicles (1). For all listed fields of use it is important that phages are highly purified with preserved biological activity. Phage and other virus purification have traditionally been carried out by CsCl density gradient ultracentrifugation, which is however difficult to be scaled-up. An alternative is chromatography already proved to be efficient for purification and concentration of certain virus types.

One of the key issues using chromatography is processing time and capacity of the resin. Novel type of chromatographic resin named monoliths was already proved to be very efficient for fast separation and purification of macromolecules as are large proteins, DNA and viruses (2,3,4).

Our aim was to investigate whether Convective Interaction Media (CIM) methacrylate monolithic columns can be implemented for purification and concentration of phage T4 (virus for E.coli). Chromatographic method using linear gradient was implemented to investigate conditions for phage elution and to establish the optimized chromatographic method applying step gradient. We analyzed phage recovery and purity together with method reproducibility.

The availability of sufficient quantities of quality DNA is always a crucial point in DNA based methods, i.e. for PCR, DNA sequencing, Southern blotting, and microarrays [1]. The same is true for the PCR-based methods for detection of genetically modified food [2]. During the production chain foods passes several physical, biological, and chemical processes, which all negatively influences on the quantity of available DNA. The phenomenon is especially expressive when high temperature treatment is performed at low pH [3]. The existing methods for DNA isolation from food cannot always fulfill the expectations of quantity and quality of isolated DNA. Furthermore they usually include 100 mg of sample and are difficult to scale-up [4]. Four major chromatographic modes are used for the separation of DNA: size-exclusion, anion-exchange, ion-pair reversephased, and slalom chromatography. Of these, anion-exchange chromatography combined with micropellicular packing is described as the most prominent technique so far [1].
Anion-exchange CIM® (Convective Interaction Media) monolithic columns allow fast and flow unaffected separation of several biomolecules, including nucleic acids [5].