mRNA Vaccines

Introduction

In vitro transcription (IVT) is at the heart of mRNA, self-amplifying RNA (saRNA), circRNA, and RNA vaccine manufacturing. The integrity, topology, sequence design, and purity of the DNA template directly influence transcription yield, product homogeneity, downstream purification burden, and ultimately patient safety.

Developers are moving toward streamlined, non-viral manufacturing concepts and in-house RNA platforms. To avoid upstream bottlenecks, they need DNA templates that scale seamlessly from research and preclinical development to GMP-aligned production – without compromising quality, documentation, or process robustness.

PlasmidFactory supports RNA development programs with high-purity plasmid DNA and bacterial backbone-free Minicircle DNA, robust linearization services, Capillary Gel Electrophoresis (CGE)-based topology analysis, Research to GMP quality grades, and proprietary POLYARESCUE® technology for stable, high-quality, transcription-ready templates.

mRNA vaccines
mRNA vaccines

The challenge

mRNA and RNA template developers commonly face bottlenecks that affect IVT performance, product consistency, and clinical translation:

  • Suboptimal IVT yields and variability: Heterogeneous DNA topologies such as open-circle, nicked, or multimeric species can reduce effective template concentration and impair transcription efficiency.
  • Undefined transcription start/stop and product heterogeneity: Circular or incompletely linearized DNA may drive read-through transcription, creating over-length or heterogeneous RNA species.
  • Backbone-derived impurities: Bacterial backbone elements such as origins of replication, antibiotic resistance markers, and non-coding DNA increase impurity load and complicate downstream purification.
  • Poly(A) tail instability: Long poly(A) stretches are difficult to maintain during cloning and amplification; shortening can lead to inconsistent poly(A) tails in the final mRNA product.
  • Scale-up friction and regulatory gaps: Transitioning from research templates to clinical-grade material often exposes missing analytics, incomplete documentation, or non-optimized linearization strategies.

PlasmidFactory addresses these challenges at the DNA template level, helping make IVT more efficient, predictable, and easier to qualify for clinical use.

The solution

Successful RNA manufacturing starts with a defined, high-quality DNA template. PlasmidFactory provides plasmid and Minicircle DNA templates designed to support efficient IVT, consistent template performance, and scalable production from early research to clinical manufacturing.

High-purity plasmid DNA for reliable IVT

PlasmidFactory provides plasmid DNA in defined quality grades, including CCC Grade with ≥95% covalently closed circular, supercoiled DNA. Topology and purity are monitored by agarose gel electrophoresis and CGE-based analysis, providing clear insight into ccc, open-circle, linear, and residual species.

This enables better template characterization, supports CMC documentation, and helps developers start IVT workflows from a well-defined plasmid DNA source.

Minicircle DNA as backbone-free IVT templates

Minicircle DNA reduces the template to the functional expression cassette while removing the bacterial backbone. The result is a compact, supercoiled, backbone-free DNA molecule with fewer unwanted sequences and a high payload fraction.

As IVT templates, Minicircles can help reduce backbone-derived impurities, simplify downstream purification, and support cleaner RNA manufacturing workflows — particularly where template purity, regulatory clarity, and process efficiency are critical.

Linearization services for defined transcription templates

PlasmidFactory provides plasmid and Minicircle DNA linearization as a fully QC-supported service, creating clean, sequence-defined templates for efficient IVT. Linearized templates help define transcription start and stop points, improve transcription accuracy, and reduce product heterogeneity.

Linearized plasmids and Minicircles can be delivered pre-configured and linearized upon request, with RNase-free formulation options for hassle-free mRNA manufacturing.

POLYARESCUE® technology for stable poly(A) elements

Long poly(A) tails are essential for mRNA stability and translation but are technically challenging to maintain in plasmid and Minicircle templates. PlasmidFactory’s proprietary POLYARESCUE® technology supports the maintenance of long poly(A) stretches, including sequences >120A, during cloning and amplification.

This NGS-supported, proprietary approach is complemented by optimized fermentation and helps generate homogenous DNA templates for consistent mRNA poly(A) tails and reliable downstream performance.

CGE analysis and comprehensive QC

Beyond manufacturing, PlasmidFactory offers CGE-based topology analysis and comprehensive QC for template DNA. This includes detailed profiling of ccc, open-circle, linear, dimeric, and residual species, as well as integrity checks after linearization.

Optional assays such as endotoxin, residual RNA, host cell DNA, protein, and microbial purity testing complement the QC package and support risk-based CMC strategies.

Scalable Supply from Research to GMP

PlasmidFactory supports RNA programs throughout their lifecycle with plasmid and Minicircle DNA from milligram to multi-gram scale. Defined quality grades — Scientific Quality, High Quality, and GMP Grade — allow template supply to match each development stage.

For preclinical and early clinical programs, High Quality (HQ) Grade provides EMA-guideline-aligned material with strong traceability, extended QC, and thorough QA oversight. For later-stage clinical and commercial applications, GMP Grade is manufactured in a dedicated GMP facility using end-to-end single-use upstream and downstream processes.

Results: More Predictable RNA Template Manufacturing

PlasmidFactory’s DNA template platform supports mRNA and RNA developers by addressing critical upstream bottlenecks before IVT begins:

  • Defined template topology: CCC Grade plasmid DNA and CGE analysis provide clear control of DNA isoforms before linearization.
  • Cleaner IVT templates: Backbone-free Minicircle DNA reduces unwanted bacterial sequences and can simplify downstream RNA purification.
  • Improved transcription efficiency: Linearized plasmid and Minicircle templates support defined IVT start/stop points, improved transcription efficiency, and more homogenous RNA products (Henschel, 2012).
  • Stable poly(A) regions: POLYARESCUE® helps maintain long poly(A) stretches for consistent mRNA stability and translation potential (Shankar et al., 2024).
  • Scalable quality: DNA templates are available from research scale to HQ and GMP Grade, with High Quality plasmid DNA established as starting material for clinical-grade RNA vaccine manufacturing (Shankar, Schmeer & Schleef, 2024; PlasmidFactory News & Stories, 2021).
  • Regulatory-ready documentation: Extended QC, traceability, and optional analytical packages support CMC and quality-by-design approaches.

Data highlights:

Verified High-Purity DNA Templates for mRNA Manufacturing

CCC Grade

AGE and CGE analysis confirm highly pure plasmid and Minicircle DNA with >95% supercoiled content and clean linearization upon request. RNase-free, pre-configured templates are available up to 10 g to support efficient, accurate, and scalable mRNA production.

Preserving Long poly(A) Stretches with POLYARESCUE®

Application

POLYARESCUE® preserves long poly(A) stretches (>120A) in plasmid DNA using proprietary NGS-supported technology and optimized fermentation. This enables homogeneous, high-quality DNA templates for efficient and reliable mRNA production.

Linearization optimizes mRNA production*

Application

Linearized plasmid and Minicircle templates improve transcription efficiency and accuracy for mRNA production, while Minicircles provide cleaner IVT templates with fewer unwanted sequences and POLYARESCUE® compatibility (*H. Henschel).

Conclusion & Summary

Whether you are building RNA vaccine platforms, saRNA programs, ex vivo cell therapies, or scaling an established mRNA product, PlasmidFactory supplies high-purity, transcription-ready DNA templates that grow with your pipeline.

Your Partner for mRNA and RNA Template Manufacturing

Whether you are building RNA vaccine platforms, saRNA programs, circRNA concepts, ex vivo cell therapy workflows, or scaling an established mRNA product, PlasmidFactory supplies high-quality, transcription-ready DNA templates that grow with your pipeline.

Our platform combines plasmid and Minicircle DNA manufacturing, defined quality grades, CGE-based analytics, linearization services, POLYARESCUE® technology, and GMP-ready production infrastructure to support efficient IVT and reliable RNA manufacturing.

By addressing key DNA template challenges — from topology and linearization to poly(A) stability, backbone-derived impurities, QC, and scalability — we help reduce upstream risk and support predictable RNA development from early research to clinical manufacturing.

With 25+ years of DNA manufacturing expertise, proprietary technologies, and flexible quality grades from research to GMP, PlasmidFactory is a trusted CDMO partner for high-quality DNA templates in mRNA vaccine and RNA therapeutic development.

References

  1. Shankar, R., Schmeer, M. & Schleef, M. (2024). Producing Plasmid DNA Template for Clinical Grade RNA Vaccine Manufacture. Methods in Molecular Biology.
  2. Shankar, R. et al. (2024). Template plasmids for mRNA production – focus on poly(A) elements. 31st ESGCT Annual Congress / Human Gene Therapy abstract.
  3. PlasmidFactory GmbH (2021). Production of plasmid DNA as starting material for mRNA vaccines. News & Stories.
  4. Henschel, H. (2012). Linearization optimizes mRNA production. Bachelor thesis, HAW Hamburg.