Self-amplifying RNAs (saRNAs) also called “Replicons” are the next generation of RNA vaccines. Their advantage over conventional mRNA vaccine platforms relies on the viral replication machinery, which amplifies the mRNA of the encoded gene of interest within target cells. In recent years, saRNA vaccines have been clinically tested with the hope of reducing the vaccination dose compared to the conventional mRNA approach. Replicons induce potent humoral and cellular responses with few adverse effects upon a minimal, single-dose immunization. Delivery of replicons is achieved with virus-like replicon particles (VRPs), or in nonviral vehicles such as liposomes or lipid nanoparticles (LNPs).
OZ Biosciences offers saRNA able to express the gene of interest up to 1 month after transfection.
These saRNAs are stabilized with 5’ Cap 1 structure and 3’ poly(A) tail and are optimized to yield improved stability & performance.
They are either unmodified, or modified with 5-methyl-Cytidine (m5C replaces U) to reduce innate immune responses.
Custom saRNA modifications
With over 20 years of nucleic acid delivery expertise, OZ Biosciences is confident in providing you with the best-in-class service for the production of high quality saRNAs.
We are able to synthesise custom saRNAs at microgram to multigram scales, from a few hundred up to several thousand bases, with a wide variety of modifications including 5’ terminal modifications with cap, internal modifications such as 5-methyl-Cytidine (other modified nucleotides on request) and 3’ modifications such as poly-A tail. Fluorescent labeling with Cy5, Cy3 and other options are also available.
saRNA have been constructed based on replicons of positive-sense ((+)-RNA) viruses (Venezuelan equine encephalitis Virus (VEEV)), where the coding sequence of the viral structural proteins is replaced with that of a gene of interest (GOI), while retaining the coding sequences of non-structural proteins (NsPs), including the viral RNA-dependent RNA polymerase. Please note that OZB saRNAs encodes also for Puromycin Resistance Cassette, which does not alter the expression of the GOI but can be used for cell selection.
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saRNA Results
Higher percentage of GFP positive cells are detected with the classic mRNA GFP (~80%) as compared to what is observed with Replicon GFP (~50%). Intensity of fluorescent signal is higher with classic mRNA GFP at 24h but decreases rapidly while the signal is stable for weeks (up to 1 month) with the Replicon GFP.
Fig. 1: GFP protein expression over time in HEK293 cells in 24-well plate cells upon lipid-based transfection with either 0,4 µg/well of Replicon GFP or 0,4 µg/well of classic mRNA GFP using NL51 transfection reagent (ratio 2:1). Photos were taken at x20 show a peak of GFP expression at 24hic mRNA GFP.
Technical Resources
Custom saRNA F.A.Q
You can easily request a quote by filling in our dedicated form available here. If you need further guidance or wish to discuss your project and specific requirements with our technical team, feel free to contact us — we will be happy to arrange a meeting at your convenience.
Custom saRNA synthesis from a provided sequence typically takes approximately 6 to 8 weeks. For projects also requiring downstream formulation, such as LNP encapsulation, please refer to our dedicated LNP formulation service for associated timelines.
The minimum order quantity for custom saRNA synthesis is 0.2 mg. For specific requirements outside this range, please contact us to discuss available options.
Yes. Codon optimization is available for the species of your choice, including human, mouse, and rat. Optimizing codon usage can significantly improve translation efficiency and protein yield in the target organism, and is particularly recommended for constructs intended for in vivo use or when high expression levels are required.
The 5' and 3' untranslated regions (UTRs) play a critical role in saRNA stability and translational efficiency. Our standard RNAs bear optimized UTR sequences for optimal expression.
All our custom saRNAs are purified and undergo rigorous quality control before delivery. We offer two levels of QC depending on your requirements:
Standard QC includes:
- Concentration measurement (spectrophotometry).
- Purity assessment via 260/280 and 260/230 absorbance ratios.
- Integrity analysis by agarose gel electrophoresis and HPLC profiling.
- Sterility testing.
Superior Grade QC includes all Standard QC checks, plus:
- Endotoxin testing.
- dsRNA quantification.
- Protein expression (when possible, i.e. fluo proteins, antibody available.)
Please refer to our saRNA quoting tool to select the QC level that best fits your project requirements.
By default, 1 mg of saRNA is supplied in a single vial at 1mg/mL. However, aliquoting is available upon request. Simply specify your preferred aliquot size or number of vials when placing your order and we will accommodate your needs.
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