Frequently Asked Questions
All the answers to your questions about our method, our products and our company, gathered on a single page.
General
What is a VHH nanobody?
A VHH nanobody is the isolated variable domain of a heavy-chain-only antibody, naturally produced by camelids such as llamas. At roughly 15 kDa, it is about ten times smaller than a conventional antibody while retaining strong affinity and specificity for its target.
Why use llamas for immunization?
Llamas produce a particularly diverse and robust repertoire of heavy-chain antibodies. Their immunizations are well tolerated, supervised by veterinary follow-up, and yield high-quality genetic material (RNA) for building nanobody libraries.
Do your programs comply with EU animal welfare regulations?
Yes, all our immunization protocols are conducted in accordance with EU Directive 2010/63 on the protection of animals used for scientific purposes, with prior ethics committee approval and continuous veterinary oversight.
Animal Immunization
Which animal species do you use for immunization?
Our core activity is immunization of farm animals, with llamas as our priority species, since their heavy-chain-only immune response is particularly well suited to generating VHH nanobodies. We also run programs in goats, rabbits and poultry depending on the project.
How do you ensure animal welfare during immunization?
Every protocol is submitted for prior review by an ethics committee, supervised by qualified veterinary staff, and follows the 3Rs principle (Replace, Reduce, Refine) in accordance with EU Directive 2010/63.
How long does an immunization program take?
A typical schedule spans about 8 to 10 weeks, including a pre-immune sample, several priming and booster injections, regular serological monitoring, and a final sample collection for RNA extraction.
Can I supply my own antigen for immunization?
Yes, immunization programs are custom-designed around the antigen supplied by the client or research project, with a protocol tailored to its nature and the intended scientific objective.
RNA Extraction
What is the most common tissue used for RNA extraction?
Peripheral blood is the most frequently used source: lymphocytes (PBL) or mononuclear cells (PBMC) are isolated from it by density-gradient centrifugation. It is the least invasive method, compatible with repeated sampling across immunization boosts.
Why use lymph nodes or spleen instead of blood?
These deeper lymphoid tissues concentrate more mature plasma cells and allow libraries to be enriched in high-affinity antibodies, at the cost of a more invasive collection than the standard blood route.
How soon after sampling is RNA extracted?
Extraction is performed immediately after sampling, the same day, to preserve RNA integrity and obtain a RIN score compatible with library construction.
What method do you use to extract total RNA?
We use a reference guanidinium thiocyanate–phenol–chloroform method, widely described in the scientific literature for RNA extraction intended for RT-PCR amplification of the VHH repertoire.
Quality Control
What is the RIN (or RINe) score?
RIN (RNA Integrity Number) and its TapeStation equivalent, RINe, are scores from 1 to 10 that quantify the integrity of an RNA sample based on its capillary electrophoresis profile. The higher the score, the more intact the RNA.
Why use Qubit instead of a standard spectrophotometer?
Qubit measures the fluorescence of a dye that binds specifically to RNA, making it less sensitive to contaminants than spectrophotometry (e.g. Nanodrop), and therefore more accurate for estimating actual RNA concentration.
What RIN score do you require before releasing a batch?
We apply a threshold of RINe ≥ 7.0 for any batch intended for VHH library construction, together with A260/280 and A260/230 purity ratios between 1.8 and 2.1.
What happens if a batch fails quality control?
A batch with insufficient integrity or purity is neither shipped nor used in a library project: a new sample is extracted and qualified before release.
Products & Ordering
What is “naive” RNA?
Naive RNA is extracted from an animal that has not undergone targeted immunization. It gives access to the species' natural antibody repertoire, useful for semi-synthetic libraries or reference studies, without waiting for an immunization cycle.
Which species do you offer?
We offer naive RNA from llama, goat, rabbit and chicken, qualified to the same standards. Other species can be assessed on request.
What is the delivery time?
In-stock batches ship within 48h on dry ice. For custom volumes or formats, a timeline is communicated at the quote stage.
What RIN score is guaranteed?
Every batch shipped has a RINe score of 7.0 or higher, with a quality control certificate (Qubit and TapeStation) provided.
Do you also offer RNA from immunized animals?
Yes, in addition to our naive RNA stocks, we design custom immunization programs — see our dedicated animal immunization page.
Scientific Applications
Are VHH nanobodies used in the clinic?
Yes, several VHH nanobodies have reached advanced clinical stages or gained approval, notably in the treatment of rare hematological conditions. Their use now extends to oncology, autoimmunity and infectious disease.
What nanobody formats are possible for these applications?
VHHs can be used alone, in bivalent or bispecific formats, fused to an Fc domain to extend half-life, or conjugated to cytotoxic agents, radioisotopes or fluorophores depending on the intended application.
Does RNACOREX develop therapeutic candidates directly?
RNACOREX focuses on animal immunization and supplying high-quality starting material (RNA, libraries). Therapeutic candidate development is carried out by our academic and industrial partners using this material.
Company & Contact
Where is RNACOREX based?
RNACOREX is a French company registered under SIREN number 953 377 900 (RCS Besançon), with its registered office located in Avanne-Aveney, in the Doubs department.
How soon will I get a response?
We typically respond within 1–2 business days to any quote request or technical question.
How do I request a quote for naive RNA?
Use our contact form specifying the species, the quantity you need and your timeline, or write directly to info@rnacorex.com.