Creative Biolabs is one of the well-recognized experts who are professional in applying advanced Hi-Affi™ Phage Display Platform and our Yeast Surface Display Platform for a broad range of sdAb discovery projects. Our Hi-Affi™ platform can contribute to generating high-quality sdAb libraries from various sources with maximized diversity and library capacity up to 1011. Subsequently, our scientists are confident in tailoring the best-fit library screening and binder validation procedures to select specific binders with high affinity around 108-1012.
Typical Features of Hi-Affi™ Phage Display Platform
- Proprietary primers are designed specifically for VHH/VNAR domain of corresponding species.
- Comprehensive phagemid vectors with different detection tag (e.g., His, HA, c-myc), suitable for various target screening.
- Freshly prepared high-quality phagemid vectors, which can achieve advanced-transfection-grade for the most sensitive applications.
- Optimized ligation strategies to increase efficiency, ensure uniformity, and keep the diversity of constructed phagemid libraries.
- Nearly 100% correct insertion rate.
- Outstanding transfection system which can maximize library capacity up to 1011.
- Comprehensive library screening procedures, specifically designed for the target of interest.
- Two-step validation strategy, which can contribute to the most reliable data.
Yeast Surface Display Platform
The yeast surface display described in Saccharomyces cerevisiae agglutinin system is proved to be an invaluable tool for the generation of sdAb. Each sdAb can be displayed in high copy number (104~105) on the surface of a single cell. Using this approach, the sdAb library with approximately 107~109 clones could be built for further screening and selection of antigen-specific sdAb binders.
Our yeast surface display platform allows not only to use purified proteins but also insoluble proteins as targets, even some unknown targets. Subsequently, sdAbs can be efficiently selected with magnetic-activated cell sorting (MACS) and fluorescence-activated cell sorting (FACS) to yield single-nanomolar affinity sdAbs. Yeast surface display platform available at Creative Biolabs is a particularly leading and influential platform due to its unique superiority from MACS and FACS.
Typical Features of Yeast Display Platform
- Eliminate artifacts due to host expression bias.
- Inclusion of epitope tags to ensure the selection of full-length sdAb.
- A secretory pathway similar to that of higher eukaryotes-ensure that only correctly folded proteins are secreted.
- Comprehensive library screening procedures, designed explicitly for insoluble proteins, cells, or unknown targets.
- Allow with quantitative and direct screening with fluorescence-activated cell sorting (FACS).
- Discriminate sdAbs with similar affinity, the rescue of relatively rare sdAbs.
Phage and yeast display are the most powerful and widely used techniques that can display sdAbs on the surface of phages or yeasts and then isolate specific sdAbs against the target of interest. Considering the natural difference of various targets, it is crucial to determine the most suitable source for library construction in the very early stage of a sdAb development project. With our professional scientists who have over ten years’ experience in antibody drug discovery, Creative Biolabs has the capacity to tailor the best-fit source and generate high-quality libraries to lay a solid foundation for your project.
Based on the source difference, qualified sdAb libraries are mainly divided into two classes, immune library and non-immune library. Thereinto, the non-immune libraries can also be subdivided into naïve library and synthetic library.
Immune sdAb Library
An immune library is constructed from natural infections or immunized donors to obtain antibodies against a particular target. As V genes collected for immune libraries contain hypermutations and had gone through in vivo affinity maturation, target-specific sdAbs with high affinity can be selected as long as an immune response can be triggered by the target. This is the best approach that is widely applicable to various immunogenic targets (e.g., soluble protein, peptide, DNA, whole cells).
Creative Biolabs has unparalleled capabilities for the construction of VHH or VNAR based single domain antibody libraries through immunized camel, llama, alpaca or even shark.
Naïve sdAb Library
A naïve library is derived from primary B-cells of non-immunized donors, in which a large repertoire of naturally rearranged V genes is collected for library construction. In general, multiple host animals will be employed in the sdAb repertoire collection and therefore contribute to a universal library that should not contain distinguish bias for a specific target. In another word, a qualified naïve library is expected to be able to isolate binders against all types of antigenic targets. In general, the affinity of selected antibodies from the naïve library is proportional to the size of the library. Due to the lack of in vivo affinity maturation against a specific antigen, an additional affinity maturation process is sometimes required to further increase the affinity of selected sdAbs.
Creative Biolabs can generate high-quality naïve sdAb library for either research purposes or industry applications. In terms of our abundant host animal sources and advanced Hi-Affi™ platform, a unique naïve library with 1011 capacity can be generated upon your request.
Synthetic sdAb Library
A synthetic library is based on the in silico design and then generated in a controlled fashion. Differ from immune or naïve libraries, in which the origin of antibody repertoires is amplified from natural source, the diversity of synthetic libraries relies on proper design. The ratio of natural and designed parts determines the classification of semi- and fully-synthetic libraries. A typical advantage of synthetic library is the composition of CDR regions that can be exactly defined and controlled. It is also a novel option to obtain camelized human single domain antibody. Similar to the naïve library, synthetic libraries are also antigen-independent, which can be used for unbiased selection of sdAbs against any targets.
Creative Biolabs has mature designs and reliable solutions for synthetic sdAb library construction. Our scientists provide a series of blueprints for either regular or human sdAb libraries, which can fulfill your project demands.
In addition to generating a fully customized sdAb library, Creative Biolabs can also provide a cost-effective option for specific sdAb discovery with a shorter lead time. In the past ten years, our scientists have generated a series of sdAb libraries in-house. These libraries were preselected based on thermostability, which can now be a great source for your projects. Some of these premade sdAb libraries are even available for licensing, which including:
- CaVHHL-1: Camel Naïve Single Domain Antibody Library
- CaVHHL-3: Camel Naïve Single Domain Antibody Library
- CaVHHL-4: Camel Naïve Single Domain Antibody Library
- LlaVHHL-1: Llama Naïve Single Domain Antibody Library
- AlpVHHL-1: Alpaca Naïve Single Domain Antibody Library
Creative Biolabs has extensive experience in providing highly customized screening strategies for novel sdAb discovery. We have overcome a great deal of challenging targets (e.g., membrane proteins, small molecules, and PTM-modified peptides) and selected specific sdAbs successfully. Focusing on the target property and your specific project purpose, our scientists are pleased to tailor a suitable strategy to achieve your goals.
If you are interested in the discovery and development of novel single domain antibodies, please do not hesitate to contact us for more details.
