Custom VHH Antibody Development Services

 

 

At Cortalix, VHH antibody development starts from a single clinical-ready foundation: our proprietary FC8TM scaffold framework. Every program we run, whether powered by ribosomal display or phage display, draws on this same humanized, thermally stable, aggregation-free framework, so you receive a lead candidate, not a starting point for re-engineering.

From ultra-diverse synthetic discovery to binder selection, engineering, and preclinical readiness, our services are fully modular. Engage us at any stage, from early discovery to downstream formatting, or anywhere in between.

 

1. Choose Your Starting Point

a. FC8TM Synthetic Discovery: Ribosomal Display + Phage Display

Our primary discovery route, and the fastest path to a clinical-ready lead. Every campaign starts within our proprietary FC8TM scaffold framework, screened first through ribosomal display across a functional diversity of up to 1014 variants, then carried seamlessly into phage display for precise enrichment and selection.

  • Animal-free, immediate start
  • Up to 11014 functional diversity via ribosomal display
  • Seamless transition into phage display for precision enrichment
  • >90% humanized, thermally and pH-stable, aggregation-free by design
  • Compatible with multiple target classes (proteins, peptides, toxins, etc.)
  • Built for clinical translation from the outset, no post-discovery re-engineering required

b. Immune Library Discovery

For projects that call for naturally affinity-matured binders, deep epitope coverage, or particularly difficult or conformational targets, we offer immune VHH library discovery based on llama or alpaca immunization with your antigen.

The immunization itself is carried out by one of our trusted specialized partners, who operate professional llama and alpaca facilities. Cortalix coordinates the process closely to ensure scientific alignment, quality, and timelines.

  • Target-specific immune response
  • High natural affinity
  • Deep epitope coverage, strong performance on membrane proteins and complex targets
  • Immunization coordinated by Cortalix, performed at a certified facility
  • Library construction, phage display, and clone selection in-house at Cortalix

Where top binders originate from immune libraries, CDRs can be grafted onto our FC8TM framework, combining natural affinity with a stable, humanized, translation-ready backbone.

2. Selection & Enrichment (all routes)

Once your library, ribosomal display, synthetic phage, or immune, is in place, we proceed with tailored phage display panning to enrich for target-specific VHHs.

We optimize each round for stringency, specificity, and diversity, based on your application (diagnostic, therapeutic, etc.).

Workflow VHH nanobodies panning

3. Clone Identification & Validation

From enriched pools, we isolate individual clones and characterize them via:

  • ELISA

Optionally, we can provide high-throughput screening of 96+ clones.

4. Downstream Engineering & Optimization

We offer additional services to tailor VHH Nanobodies to your needs:

  • CDR grafting

  • Humanization (when appropriate)

  • Affinity maturation (in silico, error-prone PCR, smart CDR1/2 diversity)

  • Fc-fusion or multimerization

  • Biotinylation or other conjugations

5. Expression & Scale-up

Expression of selected VHH antibodies in E. coli, Pichia pastoris.

  • Small-scale expression & purification
  • Scalable production-ready formats
  • Endotoxin-free options available for in vivo use
VHH nanobody development services workflow, second step expression and production

6. Optional Add-ons

  • Diagnostic assay integration (e.g., ELISA or lateral flow)

  • Functional groups and linker conjugation

  • Multimerization with HSA binding VHH for plasma half-life extension

  • Fc conjugation for plasma half-life extension

  • Fluorophore or Chelator labeling for imaging or therapy

  • Coupling to beads for analytical purposes

  • Custom formatting for analytical platforms (e.g., biosensors)

VHH Antibody Development Services: Flexibilty by Design

Our FC8TM framework unifies every discovery route we offer. Whether you choose ribosomal display for maximum diversity and speed, or immune libraries for maximum natural affinity, every VHH is built on the same clinical-ready foundation, and you never have to compromise between diversity, speed, and translatability.

Every step is fully modular, so you can engage us from early discovery to downstream formatting, or anywhere in between.

Let’s Discuss Your Project

Not sure whether to choose FC8TM synthetic discovery or immune libraries? We’re happy to advise based on your target and goals.

Contact us for a free consultation.

Frequently Asked Questions

Do you work with both synthetic and immune libraries?
Yes. Our primary route is FC8TM synthetic discovery, combining ribosomal display and phage display within our proprietary clinical-ready scaffold. We also offer immune libraries based on llama or alpaca immunization with your antigenn.
Can I supply my own immunized material?

Yes, if you already have cDNA from your isolated PBMCs or RNA from immunized animals, we can take it from there, clone it into a suitable phage vector, and build the immune library.

How unique are the VHHs that Cortalix delivers?
Our FC8TM framework, combined with ribosomal display’s functional diversity of up to 1014 variants, means the likelihood of two customers receiving the same VHH sequence is extremely small. We make every effort to ensure that each clone delivered is unique. In cases where different customers request VHHs against the same target, we take strict measures to avoid assigning the same sequence more than once
Do we have full ownership of the delivered VHH sequences ?
Yes, in almost all cases you receive full ownership of the nanobody DNA and amino acid sequences that originate from immunizations performed on your behalf. When using our proprietary FC8TM synthetic libraries, which include specially developed frameworks or patented sequence elements (e.g., in spacers or linkers), we can grant you a non-exclusive or, under certain conditions, an exclusive license for worldwide commercial use. This provides the assurance that you can freely use and further develop the VHH antibodies, while benefiting from the unique properties of our proprietary design
Can we request only selection services?

Yes, that is indeed a very logical step to start with.

Do keep in mind, though, that for any of the later development stages it is often necessary to revisit some of the preceding steps. For example, to move forward we may need to reclone the VHH into a different backbone, express it in a suitable system, or engineer it with specific linkers and functional groups to ensure functionality in the intended application. These are standard parts of the workflow and help us secure robust performance and scalability.

Just let us know what your intended use is, and we will map out the options together. Our aim is to keep the process as efficient as possible, while making sure that each nanobody is engineered and validated in a way that supports your downstream goals.

What is the typical timeline?
FC8TM synthetic discovery projects can start immediately and deliver binders in 4–5 weeks. Immune library projects depend on immunization timelines (typically 8-10 weeks) followed by discovery.
Do we only get the amino acid sequence at the end of STEP 1 or also the protein?
No. For VHHs obtained from immune libraries, we can, if desired, provide the DNA sequence of the VHH itself. The amino acid (and DNA) sequence of any spacer, linker, or the FC8TM framework itself is not disclosed, as these are part of additional services (Step 5 and/or 6). Where proprietary spacers and/or linkers are used, a non-exclusive or exclusive license can be granted for their worldwide use.
Do you guarantee a number of unique VHH binders from your library?

Yes, although conditional. If we accept the target you supply (e.g., sufficiently pure, large enough, and suitable for immobilization (biotin) on magnetic beads or a 96-well plate), we commit to a best-effort selection process. Our goal is to deliver at least two unique binders. For most targets this is realistic, but please note that 100% guarantees cannot be given, some proteins or epitopes are inherently difficult. If the first selection round does not yield two unique binders, we will repeat the process free of charge. Should this still result in fewer than two binders, we will only charge 50% of the agreed price for this step.

What is the quantity and quality of the expressed VHH from step 2?

For initial characterization, a small batch of VHH is usually sufficient (≈0,5 mg). At this stage, the nanobody is cloned into a production strain of E. coli, expressed, and purified through multi-step chromatography, yielding >95% purity. This allows us to assess affinity, specificity, and selectivity. By default, we produce the smallest batches in E. coli; for larger quantities or specific applications, production can be scaled up in Pichia pastoris or adapted to alternative systems.

Which functional groups do you conjugate?

We have extensive experience in conjugating functional groups to VHHs, with a strong focus on C-terminal cysteine conjugation. This is our preferred strategy because it delivers high coupling efficiency while maintaining VHH binding activity. Using maleimide chemistry, we routinely attach labels such as sCy7, NIR-800-CW, NOTA, DOTA, DTPA, and long-chain fatty acids. To minimize the risk of conjugation interfering with target recognition, we avoid introducing unnecessary cysteines in both the CDRs and the framework regions. The resulting conjugates typically achieve >95% purity, confirmed by LC-MS analysis.

It should be noted, however, that conjugation can sometimes alter the affinity for a given epitope, especially when the precise details of the VHH–epitope interaction are not fully understood.