PlasmidFactory’s small but powerful minicircle DNA:
From parental plasmid DNA as starting material to highly efficient minicircles, we focus on what really matters

Introducing an advanced, powerful minicircle DNA technology – PlasmidFactory‘s bespoke minicircle DNA is tailored to customer requirements, and produced using self-developed and proprietary minicircle technology.
A plasmid containing the Gene of Interest – GOI, provided by the customer, serves as starting material. The GOI is inserted into the parental plasmid, and subsequent intramolecular recombination leads to the formation of the minicircle DNA molecule, which consists almost exclusively of the GOI. The smaller size of this minimalistic, circular and supercoiled DNA compared with standard pDNA vectors makes for greater transfection and expression efficiency, while a decrease in the number of CpG motifs reduces the risk of immunogenicity. Other key advantages compared to plasmids include more stable transgene expression and reduced DNA toxicity. Just like regular pDNA, our minimal vector, the Minicircle can be used for the same common applications such as cell therapies, viral vector manufacturing and viral vector packaging as well as mRNA manufacturing.
Our minicircle DNA is available in small-scale and large scale as well as HQ grade for clinical and commercial production.
A key inventive step for us was to use Minicircle DNA to encode the CAR which reduces the amount of DNA from a conventional plasmid which is 8-9 kbp to just 4 kbp …
Minicircle features
- No bacterial backbone
(e.g. reduced CpG motifs, no replication origin) - Free of any bacterial selection markers
- Free of antibiotic resistance genes
- Free of antibiotic residues
- Smaller size compared to plasmid pDNA
- Monomeric supercoil
- Almost no cargo size restrictions
- Large-scale production available
Minicircle Manufacturing Service: Your Key to Innovation
Minicircle DNA ensures efficient transfection, high gene expression, and reduced toxicity. Ideal for CAR-T-cell production and viral vector optimization, it drives progress in clinical and biotech solutions.
Get in touch!
Insights


Minicircles have by now been tested in approximately 20 efficiency studies. In all cases, gene expression levels from the minicircle equaled or, more frequently, significantly exceeded those in the corresponding pDNA with the same expression cassette.
Expression has been tested in various cell types, tissues, and animals, using a range of transfection methods (e.g. electroporation, sonoporation, lipofection, magnetofection, hydrodynamic injection, jet injection). The McBox® by PlasmidFactory comprises the minicircle and the corresponding conventional plasmid and is very well suited to comparative laboratory experiments.
It is important to note that only equimolar comparison (same number of DNA molecules – minicircles or plasmids) is advisable.
PlasmidFactory’s minicircle CDMO service is tailored to customer requirements - also for viral vector manufacturing.
Comparison of our quality grades: Minicircle
We provide different quality levels for research and (pre-) clinical studies to ensure optimal adaption to your application. Our High Quality grade* minicircles are particularly suitable for GMP-compliant production of viral vectors and RNA, for example.
*HQ: High Quality Grade is produced in accordance with EMA guideline CHMP/BWP/2458/03 as the highest non-GMP quality standards **On requestGrades table as PDF | Research grade-MC | High Quality grade*-MC | GMP grade-MC |
---|---|---|---|
Characteristics | Applications | Applications | Applications |
Guaranteed amount of Minicircle DNA | ** | ||
Adjustment of DNA concentration included | |||
Customized filling included | ** | ||
Certified quality incl. QC Report | |||
Storage of glycerol stock of parental plasmid and retain samples for repeat orders | |||
Antibiotics-free fermentation | |||
Cultivation media according to EMA/410/01 rev.3, 2011/C 73/01 (TSE/BSE certificate) | |||
All raw materials according to EMA/410/01 rev.3, 2011/C 73/01 (TSE/BSE certificate) | |||
Characterized and documented cell bank and pilot cultivation | |||
Verified removal of bacterial endotoxins (LPS assay) | |||
Removal of RNA and proteins | |||
Specific removal of bacterial chromosomal DNA and oc-forms | |||
CGE analysis (ccc-supercoiled vs. oc plasmid topologies) | |||
Extended specification | ** | ||
Documentation acc. to GMP/GMP principles | |||
Dedicated lab | |||
QM system applied | |||
Spatially separated upstream and downstream processes | |||
Single use equipment | |||
Compliant with applicable GMP-guidelines and GMP certified |
GMP Minicircle and Plasmid Manufacture
In 2025, PlasmidFactory is proud to unveil its brand-new in-house GMP production facility, the first and only of its kind worldwide dedicated to the GMP-compliant manufacturing of Minicircle DNA. Equipped exclusively with single-use equipment, this plant Designed to meet the highest standards of good manufacturing practice, this state-of-the-art site supports the growing global demand for high-quality DNA products in cell and gene therapies (CGT), mRNA therapeutics, and vaccines. In addition to Minicircle DNA, the facility also enables flexible pDNA manufacturing under GMP conditions, offering a complete plasmid CDMO solution for development, preclinical and clinical trials and commercial manufacturing. Make use of our 25 years' pDNA manufacturing expertise - especially for challenging plasmids. With advanced quality control systems and a streamlined manufacturing process, PlasmidFactory reinforces its position as a trusted partner for therapeutics companies seeking reliable GMP plasmid and minicircle DNA manufacturing in accordance with regulatory standards.
EMA Guidelines

The term “High Quality” is consistent with the meaning embodied in EM(E)A document CHMP/BWP/2458/03 (“Guideline on Development and Manufacturing of Lentiviral Vectors”); EMA document EMA/CAT/80183/2014 (“Guideline on the quality, non-clinical and clinical aspects of gene therapy medicinal products”); and EMA document EMA/246400/2021 (“Questions and answers on the principles of GMP for the manufacturing of starting materials of biological origin used to transfer genetic material for the manufacturing of ATMPs”). PlasmidFactory seeks to ensure maximum safety and the highest quality DNA, although the plasmid production itself is not aligned to GMP standards.

… The gene transfer rate that we accomplish in primary human T cells is quite impressive and is always in excess of 50-60 %, which is 5 to 6-fold higher than with plasmid DNA.
We are aware of our responsibility towards our fellow human beings and the environment. We act in accordance with general ESG (Environmental Social Governance) criteria.