mRNA Purification Service
Overview
The success of mRNA-based therapeutics is inextricably linked to the purity of the final transcript. During in vitro transcription (IVT), a complex mixture of impurities is generated, including DNA templates, residual enzymes (such as T7 RNA polymerase), unreacted nucleotides (NTPs), and most critically, double-stranded RNA (dsRNA) byproducts. These contaminants, particularly dsRNA, act as potent triggers for the innate immune system, leading to the induction of type I interferons and premature cessation of protein translation. CD BioGlyco provides an industry-leading mRNA purification service that utilizes multi-modal separation strategies to eliminate these molecular bottlenecks. Our platform is designed to deliver mRNA with exceptionally high integrity and minimal immunogenicity, ensuring that your therapeutic cargo reaches its target with maximal potency. By integrating automated chromatography with advanced membrane filtration, CD BioGlyco provides a scalable solution.
Core Technologies
Our purification platform leverages several orthogonal separation modalities to achieve unmatched purity levels:
- Oligo-dT Affinity Chromatography
This is our primary capture step, which selectively binds the poly(A) tail of the mRNA. This effectively removes truncated transcripts that lack a tail, as well as residual DNA, proteins, and NTPs, ensuring only full-length mRNA is recovered.
- Anion-Exchange Chromatography (AEX)
We utilize high-resolution AEX to separate mRNA based on the negative charge of the phosphate backbone. This step is optimized to remove residual plasmid DNA and protein contaminants that may have co-eluted during capture.
- Hydrophobic Interaction Chromatography (HIC)
Our HIC protocols are specifically tuned for the removal of dsRNA. By exploiting subtle differences in hydrophobicity between single-stranded mRNA and double-stranded byproducts, we achieve superior reduction of immunogenic impurities.
- Tangential Flow Filtration (TFF)
For final formulation, we employ TFF for continuous diafiltration and concentration. This technology allows for rapid buffer exchange into the final delivery vehicle while maintaining high recovery rates of the concentrated mRNA.
mRNA Purification: Achieving Ultra-Pure Transcripts
Our mRNA purification service is built to accommodate the diverse needs of the biotechnology sector. We offer customizable purification tracks for various RNA modalities, including linear mRNA, self-amplifying RNA (saRNA), and circular RNA (circRNA). Our service scales range from small-batch research quantities (milligrams) for initial in vitro screening to pilot-scale and large-batch production (grams) for pre-clinical development. Furthermore, we provide specialized purification for mRNA synthesized with modified nucleosides (e.g., N1-methylpseudouridine). We understand that different chemical modifications can alter the hydrodynamic behavior of the transcript; therefore, our team optimizes the chromatography resins and elution gradients for each specific modification profile to ensure maximum recovery and purity.
Workflow
Initial Clarification and Concentration
The crude in vitro transcription (IVT) mixture first undergoes an initial clarification and concentration step, typically using tangential flow filtration (TFF) or depth filtration. This primary purification removes the bulk of process-related impurities, such as enzymes, nucleotides, and short abortive transcripts. Simultaneously, it concentrates the product and performs a buffer exchange into a solution compatible with the subsequent chromatographic steps, ensuring optimal binding conditions for the mRNA.
Affinity Capture (Oligo-dT Chromatography)
The clarified and concentrated material is then applied to an oligo-deoxythymidine (oligo-dT) affinity chromatography column. The polyadenylated, full-length mRNA specifically hybridizes to the complementary oligo-dT ligands on the resin. This highly selective capture efficiently separates the target mRNA from non-polyadenylated RNA fragments, residual DNA template, and other enzymatic contaminants, which are washed away in the flow-through, resulting in a significant enrichment of the desired product.
High-Resolution Polishing
To achieve the stringent purity levels required for therapeutic applications, the captured mRNA undergoes a high-resolution polishing step. This typically involves hydrophobic interaction chromatography (HIC) or reversed-phase (RP) chromatography, which excel at separating species based on subtle differences in hydrophobicity. This stage is critical for removing trace impurities, particularly double-stranded RNA (dsRNA) by-products, thereby dramatically reducing the molecule's potential to induce unwanted innate immune responses, a key factor in improving its safety and translational profile.
Final Diafiltration and Formulation
The polished mRNA is processed through a final TFF (diafiltration) step. In this stage, the product is diafiltered into the client's specified final storage buffer (e.g., a specific pH-stabilized, nuclease-free buffer), completely replacing the chromatography buffers. The solution is simultaneously concentrated to the precise target concentration (final titer) required for downstream applications, such as lipid nanoparticle encapsulation or analytical characterization, yielding a formulated, ready-to-use mRNA solution.
Quality Control and Certification
Every purified batch is subjected to a comprehensive suite of release tests. This includes capillary gel electrophoresis for integrity and size distribution analysis, ion-pair reversed-phase high-performance liquid chromatography (IP-RP HPLC) for purity assessment, and sensitive, orthogonal assays, such as immunoassays or dsRNA-specific fluorometric assays, to quantify residual dsRNA and host cell protein contaminants. A certificate of analysis is provided, detailing all critical quality attributes and confirming the product meets predefined specifications.
Publication Data
Journal: International Journal of Molecular Sciences
DOI: 10.3390/ijms241814267
IF: 4.9
Published: 2023
Results: In this study, Miklavčič et al. present the development and evaluation of a novel chromatographic monolith, CIM Swiper, designed for high-recovery purification of mRNA under mild conditions, specifically, at room temperature and neutral pH. The material functions as a weak anion exchanger with an isoelectric point of 5.3, enabling efficient mRNA elution within a pH range of 5–7, which minimizes degradation risks associated with alkaline environments. Using a convection-based monolithic structure, the system achieves baseline separation of mRNA (up to 10,000 nucleotides) from impurities like plasmid DNA and IVT components, with elution recoveries exceeding 80% and maintained mRNA integrity. The authors optimized purification protocols using pH and salt gradients, demonstrating scalability from analytical to preparative scales (e.g., purifying 547 mg of mRNA on an 800 mL column). This approach enhances mRNA stability, supporting therapeutic applications by avoiding harsh conditions, and offers a robust, scalable platform for producing high-purity mRNA therapeutics.
Applications
Infectious Disease Vaccines
High-purity mRNA is critical for vaccines where high protein expression and low reactogenicity are required. Our purification ensures that the immune response is focused on the antigen rather than the RNA itself.
Cell Reprogramming (iPSCs)
Pure mRNA is essential for the daily transfection required to generate induced pluripotent stem cells. Our purified transcripts maintain high cell viability, which is a prerequisite for successful reprogramming.
Rare Disease Therapeutics
We support the development of therapies for undruggable targets by providing the high-quality mRNA required for sustained enzymatic activity in the liver, CNS, or other target organs.
saRNA Research
saRNA requires specialized purification due to its large size and complex structure. Our monolithic and large-pore resins are specifically designed to handle these massive transcripts without degradation.
Advantages
Scalable Automated Platforms
We utilize fully automated, closed-system chromatography workstations. This minimizes human intervention and ensures batch-to-batch consistency, allowing for a seamless transition from discovery-scale batches to preclinical production without re-optimizing the purification parameters.
Elimination of Truncated Variants
Our oligo-dT capture technology ensures that only mRNA molecules with a functional poly(A) tail are harvested. This results in a product with high translation potential, as truncated sequences are unable to participate in the initiation of protein synthesis.
Ultra-Low Residual Protein Levels
We employ multi-step purification to ensure residual T7 RNA polymerase and other enzymatic proteins are below detectable limits. Our protein removal efficiency exceeds 99.9%, preventing unwanted anti-protein immune responses in vivo.
Comprehensive Impurity Characterization
Every purification project is backed by detailed analytical reports. We quantify residual DNA, proteins, dsRNA, and endotoxins using validated assays, providing you with the transparency required for regulatory filings and IND submissions.
Frequently Asked Questions
Customer Review
CD BioGlyco's purification service significantly improved our LNP performance. By removing the dsRNA contaminants, we saw a massive decrease in inflammatory cytokines in our animal models.
— By Dr. R.T., Senior Scientist
We transitioned our 5-gram scale project to CD BioGlyco, and the consistency was flawless. Their TFF concentration step delivered exactly the titer we needed without any loss of integrity.
— By Manager, Bioprocess Engineering
The technical depth of the CD BioGlyco team is impressive. They helped us customize a HIC protocol for our modified mRNA that doubled our previous recovery rates.
— By Dr. K.M., Head of Discovery
Associated Services
Precise determination of transcript length and detection of fragmentation using high-resolution electrophoresis.
Assessing the heterogeneity of the mRNA population to ensure batch-to-batch consistency in size and folding.
Measuring the surface charge of the mRNA-delivery vehicle complex to predict stability and cellular uptake.
Quantifying the ratio of lipids in mRNA-LNP formulations to ensure correct encapsulation and potency.
CD BioGlyco is dedicated to providing the ultra-pure molecular foundations required for the next generation of genetic medicine. Our mRNA purification service ensures that your therapeutic journey is built on a foundation of purity, potency, and safety. From milligram-scale research to gram-scale production, CD BioGlyco is your partner in purification excellence, contact us!
Reference
- Miklavčič, R.; et al. High recovery chromatographic purification of mRNA at room temperature and neutral pH. International Journal of Molecular Sciences. 2023, 24(18): 14267. (Open Access)