Creative Biolabs offers advanced phage display library construction services, including the development of custom libraries for antibody, scaffold, peptide, and cDNA formats. With extensive experience in constructing high-diversity libraries, Creative Biolabs ensures efficient identification of high-affinity binders tailored for therapeutic, diagnostic, and research applications. Their services include immune and naïve libraries in formats such as Fab, scFv, and V_HH. With a commitment to quality and innovation, Creative Biolabs delivers high-performance solutions designed to accelerate your antibody development pipeline.

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What is Phage Display Library?

Phage display library is a cutting-edge technique that allows for the expression of peptides, antibodies, or proteins on the surface of bacteriophages. By fusing genetic sequences of interest into the phage genome, the proteins are displayed on the outer surface, where they can interact with target molecules such as antigens or receptors. This technique is valuable for high-throughput screening, enabling the rapid identification of high-affinity binders for therapeutic, diagnostic, or research purposes.

Phage display revolutionizes antibody discovery by linking the genotype of the displayed molecule with its phenotype, allowing for the efficient identification of specific binders. This has made it an indispensable tool in developing drugs, diagnostics, and other bioactive molecules. The diversity of phage display libraries, which can reach over 10 billion unique clones, ensures that the chance of discovering rare, high-affinity binders is significantly increased.

In the pharmaceutical industry, phage display libraries accelerate drug discovery, allowing for the efficient identification of therapeutic antibodies. Similarly, in the field of diagnostics, phage display libraries can identify biomarkers that are vital for the early detection of diseases. This broad applicability has made phage display an indispensable tool in various sectors, from cancer research to infectious diseases.

Creative Biolabs' Phage Display Library Types

Creative Biolabs offers a range of phage display library construction services, each designed to meet the needs of different research areas:

Antibody Libraries (Immune, Naïve, Semi-Synthetic, Synthetic)

Creative Biolabs can display the interested antibody in either scFv, Fab or V_HH format to construct a high-quality antibody library. Due to the smaller size, V_HH and scFv libraries are genetically more stable than Fab libraries, Fab libraries lack the tendency to form higher molecular weight species, such as dimers and trimers, which can simplify the selection and characterization. Moreover, both human plasma cells and splenocytes from naïve or immune animals can be accepted as repertoire sources for our antibody library construction service. In addition, Creative Biolabs is able to generate fully or semi-synthetic antibody libraries as well.

• ScFv (Single-Chain Variable Fragment) Libraries

Creative Biolabs constructs scFv libraries that display antibody fragments consisting of the variable regions of both heavy and light chains connected by a short peptide linker. scFv libraries are particularly advantageous due to their small size, which enhances their genetic stability and allows for easier manipulation and expression. These libraries are ideal for discovering antibodies with high affinity and specificity, making them suitable for therapeutic, diagnostic, and research applications. The scFv fragments identified through Creative Biolabs' phage display services can also be easily engineered into full-length IgG, bispecific antibodies, CAR-T constructs, or ADCs.

• Fab (Fragment Antigen-Binding) Libraries

The Fab libraries provided by Creative Biolabs offer another powerful format for antibody discovery. Fab fragments consist of one light chain and one heavy chain fragment, retaining the antigen-binding specificity of a full antibody. Fab fragments are larger than scFvs, but they lack the Fc region, making them useful in applications where Fc-mediated effects, such as immune system activation, need to be avoided. Fab libraries are a preferred format for diagnostic applications and therapeutic development, particularly when high specificity and affinity are required. The Fab format simplifies selection, characterization, and engineering into other therapeutic formats.

• V_HH (Single Domain Antibody) Libraries

Creative Biolabs also offers single domain antibody (sdAb) libraries, which are derived from camelid antibodies. V_HH are unique antibody fragments that possess several advantages due to their small size, high stability, and ability to bind to cryptic or challenging epitopes. These characteristics make V_HHs particularly useful in drug discovery, especially for targeting inaccessible antigens or in therapeutic areas where deep tissue penetration is essential. Creative Biolabs' V_HH libraries provide a versatile platform for discovering sdAbs with high affinity and specificity for challenging targets.

• Fully Synthetic and Semi-Synthetic Antibody Libraries

For projects requiring fully synthetic or semi-synthetic antibody libraries, Creative Biolabs employs cutting-edge techniques to design libraries with tailored diversity. These libraries can be constructed to explore specific sequences or to mimic natural antibody repertoires, making them ideal for discovering antibodies against novel or rare targets. With advanced randomization methods, these libraries offer high diversity and can be optimized for developability, including factors like thermostability and reduced immunogenicity.

Scaffold Libraries

Creative Biolabs is able to generate high-quality phage display libraries for a comprehensive list of scaffolds. Our scientists are devoted to offering customized services to design specific scaffolds based on clients' demands. In addition, to achieve 100% precise mutant and over 10¹⁰ diversity, both trimer codon technology and NNK method are used in the library construction resulting in an increased randomicity, which enables the library to be more suitable for sorting and isolating the high-affinity protein or peptide targets.

Peptide Libraries (Naïve, Semi-synthetic)

To form a peptide library, Creative Biolabs can generate constrained structures with target-adapted cross-links for both naïve and semi-synthetic peptides. This structure contributes to maintaining or increasing a series of properties of peptides, such as stability, permeability, binding affinity, and resistance to protease activity.

cDNA Libraries

According to our advanced phage display platform, Creative Biolabs is capable of displaying entire cDNA products on the surface of appropriate phage system. Compared with conventional cDNA libraries, our high-quality libraries can achieve higher capacity, density, and correct orientation, which further contribute to the investigation of a lot of protein candidates. Moreover, there are various types of cDNA libraries, including standard library, full-length library, normalized library, and subtractive library, can be tailored to match our clients' demands.

Phage Display Library Construction & Screening Process

The process of phage display library construction and screening involves several key steps, which can be customized based on the specific needs of a project. Below is an overview of the general process involved in discovering a novel binder:

• Repertoire Sourcing: Sourcing the genetic material from either plasma cells, splenocytes, or synthetic DNA.
• Library Cloning: Inserting the DNA sequences into the phage genome for display on the phage surface.
• Panning: Repeated rounds of selection to enrich phages that bind to the target molecule.
• Screening: Identifying phages with the highest affinity and specificity to the target.
• Characterization: Further biochemical and structural characterization of the selected binders.

Fig. 1 Phage display library construction and screening

Creative Biolabs ensures the use of high-throughput screening methods to identify the most suitable candidates for the client's needs. Their use of advanced cloning and selection technologies guarantees the production of high-quality libraries with high diversity.

Diversity of Semi-synthetic/Synthetic Libraries

In general, Creative Biolabs employs three main approaches to design semi-synthetic or fully synthetic libraries with appropriate diversity. Our scientists normally generate libraries with a diversity of 108, while we are also able to generate libraries over 10¹⁰ or follow our clients' specific requirements.

• Hard randomization: complete diversity is introduced by using degenerate codons encoding all twenty natural amino acids.
• Tailored randomization: incomplete or biased diversity is introduced by using degenerate codons encoding a subset of natural amino acids.
• Diversification: degenerate codons are synthesized using trimer phosphoramidites corresponding to 20 natural amino acids, which exclude stop codons.

Phage Display Systems

Based on the interest protein and specific project objective, Creative Biolabs is able to tailor the most suitable phage display system (M13, T4, or T7) for the library construction.

• M13 Phage Library Construction
• T4 Phage Library Construction
• T7 Phage Library Construction

Fig. 2 Phage: Structure and genome

Table 1. Typical phage display systems.

λ Phage

In addition to regular M13, T7 or T4 phage, λ phage is an ideal vehicle to carry the DNA fragments due to its simple structure and flexible DNA. By employing multiple lambda vectors, Creative Biolabs can offer specific genome library construction service to generate qualified genome library with over 95% coverage from either genomic DNA, chromosomes, or microbes. In addition, our professional scientists are also available to generate lambda-based cDNA library as an alternative service.

Different Applications of Phage Display Library Construction Service

Therapeutic Antibody Discovery: Phage display libraries allow for the rapid identification of antibodies that specifically target disease-causing proteins, such as those found in cancer, autoimmune diseases, and infectious diseases. Creative Biolabs leverages both naïve and immune antibody libraries to provide tailored solutions, ensuring high diversity and developability. By using our advanced library construction technologies, we enable clients to rapidly progress from discovery to preclinical development, ensuring that therapeutic antibodies are ready for downstream applications.

Diagnostic Development: Creative Biolabs' diagnostic-focused phage display services are tailored to ensure the development of high-affinity antibodies for diagnostic kits. Our expertise in antibody engineering ensures that the antibodies developed through phage display are optimized for diagnostic performance.

Basic Research: Phage display libraries enable researchers to study protein-protein, protein-DNA, and protein-ligand interactions, contributing to a deeper understanding of cellular processes and disease mechanisms. This foundational research is crucial for the identification of novel therapeutic targets and biomarkers. Creative Biolabs supports basic research applications by offering customizable phage display services that meet the unique needs of research projects. Our high-diversity libraries, combined with expert guidance, allow researchers to explore complex biological interactions and advance the understanding of molecular mechanisms.

Why Choose Creative Biolabs?

Creative Biolabs offers unmatched expertise in phage display library construction, with over 20 years of experience in the field. Our team of specialists provides personalized service, working closely with clients to design and implement projects that meet their specific research needs. Our proprietary technologies, large-scale custom libraries, and full project support make us a trusted partner in the discovery and development of antibodies, peptides, and proteins for therapeutic and diagnostic applications.

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FAQ

1. What is the principle of phage display technology?

   Phage display technology fuses and displays exogenous peptides and phage capsid proteins on the surface of phages, performs high-throughput screening and enrichment, and conducts qualitative analysis of clones with required functions. The display objects of this technology are antibodies, antibody fragments, peptides, cDNA, and so on.

2. What are the advantages of phage display in the construction of antibody libraries?

   In the study of antibody libraries, phage display technology can construct and screen the B cell antibody libraries of humans and other animals in vitro, avoiding the steps of immunity and cell fusion so as to shorten the experimental cycle and increase stability. The technology also has the advantages of large screening capacity, mass fermentation production, simple experimental method, and so on.

3. What research directions can phage display technology be applied to?

   According to the different display molecules, it can be roughly divided into the following two categories:
   1) Protein/antibody: diagnostics, drug navigation, protein structure analysis, humanized modification, and customization of scientific research antibodies.
   2) Random peptide library: protein-protein (ligand receptor, information transmission, antagonist/inhibitor, etc.), protein-DNA, diagnostics, neutralization activity, drug and drug navigation, enzyme, and substrate.

4. What are the screening methods for phage display?

   There are two main screening methods for phage display: magnetic bead labeling and immune tube screening. The difference between the two is that the former has more positive clones, while the latter has fewer positive clones but higher affinity. In general, the magnetic bead labeling method is preferred for screening, and then it is decided whether or not to increase the immune tube screening step according to the results. The basic principle of the two methods is the specific binding of antigens and antibodies.

5. How can the screening process displayed by bacteriophages ensure that the antibodies that are screened for interference can retain the desired antibodies?

   The principle of selection is actually an experimental process based on the specific reaction between antigens and antibodies. Specifically, the specific binding between the antibody sequence displayed on the surface of the phage and the antigen makes the specific antibody sequence continuously enriched. However, in the process of screening, there must be non-specific binding between bacteriophages of 10¹² or higher and antigens, so after the screening is over, another ELISA identification will be carried out to exclude the non-specific binding antibody clones. Secondly, if there are several highly homologous targets that need to be distinguished at the same time, a closed group can be set up to seal off the cross-binding positive clones in advance, and the remaining phage library can be used to screen specific targets.

6. How much will be detected by monoclonal clone sequencing in the phage antibody library?

   For the evaluation of the antibody library, 20–50 clones are randomly selected and sequenced to evaluate the diversity and titer of antibodies.
   For the positive clones after screening and ELISA detection, the 10-15 clones with the best ELISA results are generally selected for sequencing.

7. What is the capacity of the phage antibody library finally obtained? How to ensure that the coverage meets the requirements after repackaging?

   Finally, the phage antibody library was 20–30 ml, and each tube of 1 ml was assembled separately. In general, as long as the number of clones in each tube is more than ten times the capacity of the library, all the sequences can be guaranteed. If the capacity of the immune antibody library is 10⁹, as long as the concentration of bacterial liquid in each tube is more than 10¹⁰, all antibody sequences can be covered.

Resources

Use the resources in our library to help you understand your options and make critical decisions for your study.

All listed services and products are For Research Use Only. Do Not use in any diagnostic or therapeutic applications.