mRNA

Key Facts about mRNA

Messenger RNA (mRNA) is a single-stranded ribonucleic acid molecule that carries genetic information from DNA to the ribosome, where it directs the synthesis of a specific protein. Unlike traditional biologics, therapeutic mRNA is not produced inside living host cells, but generated cell-free in an enzymatic in vitro transcription (IVT) reaction — making mRNA manufacturing fundamentally different from classical mammalian or microbial bioprocesses.

mRNA molecules are inherently unstable, highly susceptible to ribonucleases (RNases), and sensitive to temperature, pH, and ionic conditions. Their integrity, capping efficiency, poly(A) tail length, and the level of double-stranded RNA (dsRNA) by-products directly determine translational efficiency, immunogenicity, and therapeutic safety — making tightly controlled bioreactor conditions, low-shear environments, and thermal homogeneity essential for high-quality mRNA production.

As a versatile platform technology, the same manufacturing process can be rapidly adapted to new targets by exchanging the DNA template — enabling vaccines (e.g. COVID-19, influenza, RSV), cancer immunotherapies, protein replacement therapies, and gene editing tools such as CRISPR-Cas9 delivery. These properties shape the requirements for any bioreactor used in mRNA production: precise temperature control, gentle mixing, minimal hold-up volume, and operation under fed-batch or continuous IVT regimes.

mRNA illustration – messenger RNA strand inside lipid nanoparticle for therapeutic vaccine bioreactor production

The mRNA Process: From Lab to Therapy

The process of developing mRNA for therapeutic applications merges molecular biology, genetic engineering, and bioprocess technology — requiring a series of precisely controlled steps from initial sequence design to delivery into patient cells.

  1. mRNA sequence design and optimization

    The journey begins with rational design of the mRNA sequence: codon optimization, GC content, 5′ and 3′ UTRs, and poly(A) tail length are tuned to enhance stability, translation efficiency, and expression fidelity. Modified nucleosides such as N1-methylpseudouridine dampen innate immune activation while preserving protein output, and computational tools refine secondary structure to minimize uridine content and avoid sequences prone to dsRNA formation.

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  2. In Vitro Transcription (IVT)

    A linearized DNA plasmid carrying a T7, T3, or SP6 promoter is incubated with RNA polymerase, NTPs, a cap analogue or co-transcriptional capping system, magnesium, and supportive enzymes (RNase inhibitors, pyrophosphatase). Yield depends strongly on NTP and Mg2+ stoichiometry, temperature, pH, and reaction time. Fed-batch IVT in controlled bioreactors has pushed mRNA titers above 10 g/L while reducing dsRNA byproducts compared to conventional batch reactions — a key step toward continuous, GMP-ready mRNA biomanufacturing

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  3. Purification and quality assurance

    The crude IVT mixture is purified through DNase digestion, tangential flow filtration, oligo-dT affinity capture, ion-exchange chromatography, and ion-pair reversed-phase HPLC for dsRNA removal. Critical quality attributes — mRNA integrity, capping efficiency, poly(A) tail length, dsRNA content — are characterized by IP-RP HPLC, anion-exchange HPLC, capillary gel electrophoresis, and orthogonal bioassays. Robust QC is essential because even trace dsRNA can trigger innate immune sensors and reduce protein expression up to 1000-fold. 

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  4. mRNA encapsulation and delivery

    Purified mRNA is formulated into lipid nanoparticles (LNPs) comprising four lipid classes: an ionizable cationic lipid, helper phospholipid, cholesterol, and PEG-lipid. Their molar ratios determine encapsulation efficiency, particle size, polydispersity, biodistribution, and tissue tropism. LNPs are most commonly produced by rapid microfluidic or T-junction mixing of an ethanolic lipid phase with an aqueous mRNA phase, followed by buffer exchange and sterile filtration — with flow ratio, total flow rate, and lipid composition tightly controlled to deliver consistent particle quality at clinical and commercial scale. 

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  5. Scaling up production with bioreactors

    Scaling up mRNA production from research to clinical and commercial supply requires bioreactors that provide tight control over temperature, pH, mixing, and feed addition for cell-free IVT — and for upstream plasmid DNA fermentation. Single-use and small-scale bioreactors enable parallel screening of IVT conditions, NTP feeding strategies, and Mg2+ profiles, while linear, predictive scale-up from millilitre development volumes to litre-scale GMP production is a hallmark of modern Biopharma 4.0 mRNA platforms supporting fed-batch and continuous IVT modes.

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  6. Clinical application and monitoring

    The final mRNA therapeutic is administered to patients through routes appropriate to the target disease and tissue. Patients are closely monitored for therapeutic outcomes and adverse reactions — with efficacy measured by target protein expression levels and clinical improvement.

Capabilities

The Role of Bioreactors in mRNA Production

The Applikon Mini bioreactor stands out as a critical tool in the production of mRNA — offering the precision and scalability needed for this cutting-edge field. As biotech companies continue to explore and expand the applications of mRNA, the Applikon Mini bioreactor remains an essential component in the development of the next generation of RNA therapies.

The field of mRNA therapeutics is rapidly evolving, with mRNA technology offering promising new avenues for treating and preventing diseases. The production of mRNA, from design to large-scale manufacturing, relies on sophisticated equipment that provides the necessary precision and scalability.

Applikon Bioreactor Types for mRNA

All Applikon bioreactor formats can be configured for mRNA-related workflows — from upstream plasmid DNA fermentation in E. coli to fed-batch IVT and downstream conditioning steps. The portfolio covers small-scale process development up to GMP production of mRNA therapeutics.

Type Scale Key Use Cases mRNA-Specific Features
Applikon MiniBio
glass small-scale bioreactor		 0.25–1 L Process development for fed-batch IVT, NTP/Mg2+ screening, plasmid DNA fermentation, scale-down models Low working volume reduces costly NTP and enzyme consumption; parallel runs for DoE; scalable mRNA process development
Applikon glass autoclavable bioreactors
for mRNA workflows		 2–20 L Plasmid DNA fermentation, optimization of fed-batch IVT, scale-up/scale-down studies for mRNA bioprocess development Flexible vessel configuration, multi-gas sparging, multiple sensor ports for PAT (HPLC sampling, FTIR/Raman), high reusability
AppliFlex ST
single-use bioreactor for mRNA		 0.5–15 L Single-use plasmid DNA fermentation, GMP-ready fed-batch IVT, clinical-scale mRNA production, fast tech transfer Disposable vessels for closed processing, fast turnaround, reduced cross-contamination risk — critical for multi-product mRNA facilities
Stainless-steel bioreactors
for large-scale mRNA manufacturing		 20–5000 L Commercial-scale plasmid DNA fermentation, repeated GMP production runs supporting industrial mRNA vaccine and therapeutic supply CIP/SIP capability, robust agitation control, validated for cGMP manufacturing, scalable to global mRNA supply demands
Clinical Use Cases

Applications of mRNA Technology

Messenger RNA technology has rapidly advanced to the forefront of biomedicine — offering novel therapeutic applications across a wide range of diseases by exploiting the fundamental biological process of translating mRNA into proteins within cells.

Advantages of the Applikon Mini Bioreactor for mRNA Production

  • Precision and Control

    Precision and Control

    Precise control over the cultivation environment — crucial for producing high-yield mRNA. Careful regulation of temperature, pH, and aeration ensures optimal cell density and health throughout the IVT process.

  • Scalability

    Scalability

    Designed to facilitate both research and commercial-scale production — supporting the scalable manufacturing of mRNA therapeutics from early development through to clinical trial and commercial-scale manufacturing.

  • Integration

    Integration

    Compatible with various cell culture systems and bioprocessing steps — enabling an integrated approach to producing mRNA-based treatments and supporting seamless workflows from IVT through purification and encapsulation.

End Products

Cell Therapy

Cell Therapy
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FAQ - mRNA

mRNA stands for Messenger RNA — a type of RNA that carries genetic information from DNA to the cell’s protein-making machinery. As a molecular intermediary, it converts genetic instructions from DNA into the proteins that perform critical functions within our cells. In therapeutic applications, synthetic mRNA is designed to encode specific therapeutic proteins — prompting cells to produce these proteins in situ, providing a versatile platform for disease treatment and prevention across vaccines, cancer immunotherapy, protein replacement therapy, regenerative medicine, and gene editing.

The production of mRNA therapeutics involves six key steps:

  1. mRNA sequence design and optimization, including codon optimization and UTR engineering;
  2. In Vitro Transcription (IVT) to synthesize the mRNA from a DNA template;
  3. Purification and quality assurance using HPLC or affinity chromatography;
  4. Encapsulation within lipid nanoparticles (LNPs) or other delivery vehicles;
  5. Scaling up production using bioreactors for clinical and commercial manufacturing
  6. Clinical application and patient monitoring for therapeutic outcomes and safety.

Beyond vaccines, mRNA technology has a wide range of therapeutic applications. In cancer immunotherapy, mRNA is used to develop personalized cancer vaccines and CAR T-cell therapies. For protein replacement therapy, mRNA can enable in vivo production of missing or defective proteins for conditions like cystic fibrosis and hemophilia. In regenerative medicine, mRNA encoding growth factors such as VEGF is being explored for tissue repair. Additionally, mRNA is critical for delivering CRISPR-Cas9 gene-editing components to correct mutations at the DNA level.

The Applikon Mini bioreactor stands out as a critical tool for mRNA production because it offers precise control over the cultivation environment — including temperature, pH, and aeration — which is crucial for producing high-yield mRNA. Its scalable design facilitates both research and commercial-scale production, and its compatibility with various cell culture systems and bioprocessing steps enables an integrated approach to producing mRNA-based treatments. Available in 250 mL, 500 mL, and 1000 mL volumes, it is a true scale-down of the traditional lab-scale bioreactor with fully scalable results.

Naked mRNA is inherently unstable and susceptible to degradation by ribonucleases present in bodily fluids. It is typically encapsulated within lipid nanoparticles (LNPs) or other delivery vehicles to protect the mRNA and facilitate its entry into cells. This encapsulation process involves optimizing the size, charge, and composition of the LNPs to ensure efficient cellular uptake and endosomal escape — allowing the mRNA to reach the cytoplasm where it can be translated into the target protein.