Minicircle DNA Vector Technology

Get sustained, episomal gene expression free from foreign DNA - great for model animal generation and gene therapy research

Minicircles are episomal DNA vectors that are produced as circular expression cassettes devoid of any bacterial plasmid DNA backbone. Their smaller molecular size enables more efficient transfections and offers sustained expression over a period of weeks as compared to standard plasmid vectors that only work for a few days. For dividing cells, expression of the minicircles lasts up to 14 days. For non-dividing cells, expression of the minicircles drops slightly after the first week, but then can continue to express the transgenes for months.

BioCat's partner SBI developed multiple minicircle vector formats with different promoters and fluorescent reporters.

• Episomal expression sustained over weeks
• Foreign DNA-free
• More efficient transfections from small plasmid size
• No integration into the genome
• Optimized E. coli minicircle production strain
• Works in vitro and in vivo

Production of minicircle DNA

The Minicircle (MC) DNA elements are generated by intramolecular (cis-) recombination from a parental plasmid (PP) mediated by PhiC31 integrase. The full-size MC-DNA construct is grown in a special host E. coli bacterial strain ZYCY10P3S2T harboring an Arabinose-inducible system to express PhiC31 integrase and I-SceI endonuclease simultaneously.

Adding arabinose to the media turns on the integrase and endonuclease genes. The PhiC31 integrase produces the MCDNA molecules as well as PP-DNA backbone from the full-size MC-DNA construct. The Sce-I endonuclease then degrades the PP-DNA backbone preventing immune responses.

It is highly recommended to use the MC-Easy Minicircle DNA Production Kit, which contains optimized reagents for perfect Minicircle DNA preparations and the E. coli  producer strain ZYCY10P3S2T. A second version of the kit is  available without competent cells.

E. coli producer cells can be ordered as a separate product.

Minicircle DNA Vector Options

Our partner SBI has created a set of minicircle parental cloning vector formats to choose from. Select from CMV or EF1a promoters, GFP, RFP and Puro markers. The minicircle parental cloning shRNA vector formats feature either CMV or EF1a expressing the markers and a downstream H1 promoter to express high levels of the cloned shRNA sequence. See the table below for the particular MCS cloning sites for each of the minicircle DNA vectors.

Please note

Parental minicircle plasmids and the ZYCY10P3S2T Producer Bacterial Strain are available for purchase by not-for-profit researchers only. Commercial users may purchase pre-made mcDNA [ready-to-transfect] only. For any other purposes, including the ability to buy the parental MC production system, commercial users should contact us at BioCat for additional details.

Minicircle Service

In cooperation with SBI BioCat also offers custom parental plasmid cloning and mcDNA production to both not-for-profit and commercial end users. Please contact us if you are interested in this service.