Accelerate your monoclonal antibody development program with ProteoGenix antibody phage display services and get your antibodies in less than 2 months! Our naïve libraries consist of antibodies from various species and in various formats (Fab, scFv, or VHH), easily adapted to recombinant monoclonal antibody production. Benefit from our strong guarantees and receive at least 3 relevant binders with high affinity and screened in the application of your choice (ELISA, WB, or Flow Cytometry). Thanks to our highly diversified libraries and vast experience in phage display earned through more than 250 projects, we help you develop new antibodies for therapy, research, and diagnostics.

5 good reasons to choose phage display for your antibody development project

There are now many ways of developing antibodies. The best known are hybridoma development, single B-cell sorting and phage display. Each method has its strengths, and choosing the most suitable method for your project is sometimes difficult. If you are hesitating between these different technologies, here are 5 good reasons to choose phage display:

  • Phage display enables human antibodies to be developed directly, making it particularly attractive therapeutic antibody discovery. Although the service is more expensive at the outset, it allows you to bypass the need for a lengthy humanization step. Also, if you are working on cancer and autoimmune diseases research, we offer you the possibility of supplementing our naive library with an immune library created from patients suffering from these diseases to optimize your chances of discovering antibodies capable of reaching clinical stages.
  • The phage display makes it possible to develop antibodies against toxic antigens that would be impossible to use with technologies requiring an immunization protocol.
  • As it is possible to dispense with immunization, phage display enables antibodies to be generated rapidly. Developing an antibody from a naive library takes less than 2 months, whereas a project requiring immunization often takes more than 3 months.
  • The phage display has no species limitation. Whether you want to develop human or VHH antibodies for therapeutic applications or rabbit antibodies for diagnostic applications, there is no limit!
  • This is a technique that can be used for large-scale applications. The phage display provides easy access to the antibody sequence, opening the door to recombinant production or various engineering steps, such as the generation of ADCs or bispecifics.
Naïve libraries Immune libraries
Species Human, rabbit, camelids (camel, llama, alpaca) No limitation except humans
Formats Fab, scFv, VHH Fab, scFv, VHH
Number of binders ++ +++
Affinity of binders ++ +++
Potential immunogenicity issues No Yes
Animal use No Yes
Timelines 4-5 weeks 11-16 weeks + 4-5 weeks
Price + ++

Antibody library generation is a vital first step in all phage display projects. The process encompasses the recovery of the naïve or immune antibody repertoire from specific host species by harvesting their B lymphocytes (B cells) or isolating PBMCs (peripheral blood mononuclear cells) by density gradient centrifugation of blood samples. The diversity of these repertoires is subsequently seized by mRNA extraction, cDNA synthesis, and PCR-mediated amplification of antibody-encoding genes.

Naïve libraries are prized for their versatility (adaptability to different projects/antigens) while immune libraries are considered more labor-intensive and reserved for especially challenging projects aiming to boost antibody affinity and selectivity.

Interested in our naïve library screening screening service or in constructing an immune library? Please feel free to contact our dedicated account manager.

Library Format Species Size (clones)
LiAb-SFCANCERTM scFv & Fab Human - 48 donors with 7 different cancers: prostate, colorectal, renal, lung, skin, melanoma, acute myeloid leukemia - Ideal for cancer antibody development 3.81 X 1010
LiAb-SFCOVID-19TM scFv Human – Donors that recovered from COVID-19 – Ideal for the identification of SARS-CoV-2 binders 1.19 X 1010
LiAb-SFMAXTM scFv & Fab Human – 5 different ethnic groups – 368 donors for maximized diversity 5.37 X 1010
LiAb-SFaTM scFv Human 1.5 X 109
LiAb-FabTM Fab Human 2.00 X 1010
LiAb-VHHMAXTM VHH Camel, llama, alpaca – 57 animals – Ideal for nanobody generation 1.51 X 1010
NEW! LiAb-SFDogTM scFv & Fab Dog – 6 different breeds for maximized diversity 1.05 X 1010
LiAb-SFRabTM scFv & Fab Rabbit – 4 different breeds for maximized diversity 1.09 X 1010
LiPep-12TM Peptide 12-mer / 1.00 X 109
LiPep-7TM Peptide 7-mer / 1.00 X 109

ProteoGenix developed a large choice of proprietary phage display libraries that you can adapt to all your projects. Our goal is to fulfill all your unique requirements and to always push the boundaries of innovation by creating new and better phage display libraries. Whether you need a fully human antibody or a nanobody for therapeutic applications or a high-affinity rabbit antibody for diagnostic applications, our libraries will help you overcome your most difficult challenges. Feel free to contact our account manager for more information.

Our antibody phage display service process

Immune library

Antigen procurement or design and production

  • Peptide/small molecules: conjugation to carriers
  • Protein production including gene synthesis
  • Cell overexpressing target protein

Immune library construction (optional)

  • PBMC isolation
  • RNA extraction and cDNA synthesis
  • VH and VL PCR amplification
  • Library construction and QC

Library screening and biopanning

  • Screening of naive or immune library against antigen
  • 4-6 rounds of biopanning

ELISA screening of single phage binders

  • ELISA screening and validation until identification of at least 3-10 different binders

DNA extraction antibody sequencing

Naive library

Antigen procurement or design and production

  • Peptide/small molecules: conjugation to carriers
  • Protein production including gene synthesis
  • Cell overexpressing target protein

Library screening and biopanning

  • Screening of naive or immune library against antigen
  • 4-6 rounds of biopanning

ELISA screening of single phage binders

  • ELISA screening and validation until identification of at least 3-10 different binders

DNA extraction antibody sequencing

Step Content Timelines Deliverables
Library construction (only for immune libraries)
  • Animal immunization and titer tests
  • Cell isolation (spleen, bone marrow, PBMC)
  • RNA extraction
  • cDNA synthesis
  • VH and VL PCR amplification
  • cDNA assembly
  • Phagemid synthesis and cloning
  • Library QC
11-16 weeks
  • Progress report
Library screening and biopanning
  • Screening of the naïve or immune library
  • 4-6 rounds of biopanning
4-5 weeks
  • Progress report
ELISA screening
  • Screening and validation by ELISA until at least 3-10 different binders are identified
4-5 weeks
  • Progress report
DNA extraction and antibody sequencing
  • Phage DNA extraction and antibody sequencing
4-5 weeks
  • Detailed report
  • DNA sequence of the best binder Full ownership of the sequences

Options available:

  • Additional screening of single phage clones by ELISA against a specific protein/peptide/small molecule/cell
  • Additional screening of single phage clones by WB
  • Additional screening of single phage binders by flow cytometry on cells
  • Assessment of the affinity of single phage binders
  • Panning against cells overexpressing antigen of interest with library depletion against control cell

Satisfied antibody phage display customer testimonial

“I requested ProteoGenix’s services for the generation of neutralizing anti-COVID-19 antibodies by Phage Display. They designed an optimised strategy for this purpose which led to great results, with 4 antibodies identified as cross-reactive and neutralizing against all the current variants of concerns.

During the whole project, Proteogenix strived to ensure the best quality of their final deliverables, especially by including additional screenings against emerging variants as the pandemic evolved.

Their proactivity was key to obtaining promising and relevant blocking antibodies in only a few months. I highly recommend them for both their level of expertise and the personalised service they offer.”

“All three of the antibodies you delivered were reformatted into IgGs and worked well. Interestingly two were d1 binders, and one was a d1/d2 binder when we domain mapped them here. They were good “protein X” blocking antibodies. But none were “protein Y” blockers. They express reasonably well. Overall we are quite happy with them.”

“ProteoGenix has been generous and sincere in supporting an academic laboratory like ours. They were able to identify several antibody sequences via phage display against a protein antigen and they screened twice more phages than initially planned to help us succeed in our project. ProteoGenix team was reactive and diligent in their replies and services.”

“We are developing a novel immunotherapy and needed a highly potent monoclonal antibody. Currently the development of a novel antibody requires lengthy and expensive humanization process. We thus decided to screen for binders a human antibody library via phage display screening instead of humanizing a murine antibody. Proteogenix proposed just that. We provided our purified target antigen and in only one month several high affinity binders were obtained. We were able to quickly clone and produce a monoclonal antibody from the sequences provided. What should have taken 6 to 8 months was done in 2 for a fraction of the cost and for an equivalent quality.”

“I requested ProteoGenix’s services for the generation of antibodies against a malarial protein by phage display. Their naive human library, which is comprised of 368 donors, is a unique resource which was one of the criteria I used to select their company. They optimized their standard screening strategy to be able to identify two specific clones, that they then expressed with very high yields in their proprietary XtenCHOTM cell line. I highly appreciated their level of expertise and their commitment to go beyond expectations, and I would recommend them for their reactivity and the high quality of their services.”

“We requested ProteoGenix’s services for the development of a monoclonal antibody for flow cytometry. They were able to identify three candidates that all bound well and specifically to our antigen. The best one was validated in our final application and the results were published in an international journal. We were overall satisfied with the quality of the final product and its results.”

“We requested ProteoGenix’s services for the development of antibodies against a specific surface protein by phage display. Their naive human library was built from 368 donors for maximized diversity. This unique quality and their reactivity convinced us to work with them. They successfully identified various candidates that all bound well and specifically to our antigen. I appreciated their expertise for the high quality of their services as well as their good responses to my questions for this project.”

“We have been working together with ProteoGenix since 2020. Using phage display, they helped our team to develop several antibodies with effective blocking effects. We are pleased with their services and look forward to continue working together with them as we advance our research and bring the biologics to clinical stage.”

Case study: antibody generation against a small molecule by phage display

Project Requirements

One of our customers requested a human antibody against a small molecule. The small molecule was conjugated to different carriers to achieve optimal coating. Biopanning was performed using our human naive library of high diversity.

A total of 192 single phage binders were screened and validated by ELISA. 10 antibody sequences were required.

Phage output (pfu) Phage output (pfu)
Rounds Phage input (pfu) Panning with antigen coating Panning with no coating (negative control)
1 2.0×1012 8.9×106 3.4×106
4 1.0×1012 4.0×107 2.5×106

There is an obvious enrichment in anti-antigen binders even if it is difficult to remove the binders to carriers (known phenomenon).

Round 3 Round 3 Round 4 Round 4
Phage quantity (pfu/well) Antigen Control Antigen Control
6×1012 3.035 2.584 3.630 3.451
2×1012 2.798 1.709 3.308 3.007
6.7X1011 1.508 1.069 3.028 2.128
2.2×1011 0.5666 0.5024 2.976 1.885
7.4×1010 0.1712 0.1932 2.581 1.704
2.5×1010 0.08020 0.09040 2.033 1.317
8.2×109 0.06090 0.09140 1.931 1.054
2.7×109 0.01620 0.01740 0.7235 0.7526
9×108 0.01290 0.01460 0.2341 0.2432

Although there are many unspecific binders (known phenomenon), an obvious enrichment in anti-antigen binders is observed (data in bold).

Clones Ag-carrier 1 Ag-carrier 2 Ag-carrier 3 No coating Carrier 1 Carrier 2 Carrier 3
A6 4.698 4.743 4.466 0.118 0.100 0.092 0.117
A9 4.769 4.766 4.420 0.100 0.092 0.078 0.074
B1 4.716 4.804 4.452 0.353 0.584 0.422 0.187
B2 4.494 4.482 4.874 0.081 0.122 0.109 0.100
D1 4.862 3.989 4.540 0.170 0.488 0.313 0.123
D8 4.862 4.090 4.486 0.057 0.106 0.102 0.059
F4 4.214 3.352 5.306 0.051 0.110 0.123 0.059
H2 4.797 4.537 4.588 0.084 0.213 0.188 0.112
H11 4.722 4.604 5.049 0.103 0.218 0.262 0.138
1A11 4.407 4.528 4.562 0.054 0.086 0.115 0.079
1G1 4.956 4.381 5.218 0.076 0.114 0.138 0.077

We generated 11 unique clones that specifically and strongly bind to the small molecule antigen.

Our customer decided to express these 11 clones as recombinant antibodies and to order the screening of 192 additional single phages, which resulted in the identification of 7 new unique sequences.

Learn more about our capabilities of antibody phage display services. Discover our complete report by clicking on the “DOWNLOAD PDF REPORT” button.

Case study: generation of an antibody cocktail against SARS-CoV-2

Project Description

Since Omicron became widespread, more and more treatments have been rendered ineffective against SARS-CoV-2. To provide timely solutions to this crisis, we partnered with Aseem Healthcare and Trident Biopharm Solutions to develop a new broadly neutralizing antibody cocktail.

After extensive testing, the cocktail proved not only to be active against major variants but also to outperform currently FDA and EMA approved and authorized treatments.

Project Workflow
Step 1 Immune COVID-19 Library Construction Milestone: scFv library diversity > 109
Step 2 Antibody Phage Display
  • Library enrichment via phage display using the receptor-binding domain (RBD) of SARS-CoV-2 variant Alpha
  • Identification of clones able to cross-react with all other major variants
  • Competitive ELISA using Alpha’s RBD and the human ACE2 receptor
Milestone: isolation of 9 cross-reactive + neutralizing binders
Step 3 Recombinant Expression
  • Fast recombinant expression in XtenCHO™ to characterize the bioactivity and stability of binders
Milestone: all but 1 binder displayed high activity and stability
Step 4 Testing for Neutralizing Activity Against Major Variants
  • Rapid screening using ProteoGenix’s SARS-CoV-2 Surrogate Virus Neutralization Test (sVNT) Kit
  • Validation of the bioactivity via Plaque Reduction Neutralization Tests (PRNT)
  • Milestone: identification of 4 mAbs with strong neutralizing activity against all variants

Results Of Sars-cov-2 Neutralization Tests

Inhibition Cocktail Results
Inhibition (%) of major variants of SARS-CoV-2 by each individual antibody of the AH-5-COV cocktail determined via PRNT test
Variant/ mAb England 02/2020 Alpha Beta Gamma Gamma Omicron
A5 0.06599 0.03245 0.1790 0.1693 0.1693 No inhibition
A9 6.641 4.864 6.719 18.72 18.72 No inhibition
A11 0.09098 0.04757 0.01510 0.02326 0.02326 0.005713
B4 0.04742 0.03678 > 0.08* 0.006945 0.006945 > 0.08*
B7 > 0.08* > 0.08* 0.02949 0.01878 0.01878 0.04936
B9 0.2141 0.2494 No inhibition No inhibition No inhibition No inhibition
D8 0.01964 0.01326 1.008 0.7628 > 0.08* 0.3364
G4 0.2273 0.05904 0.4028 0.2017 0.07378 No inhibition
Positive control 0.3602 0.3815 0.4183 0.3505 0.3634 No inhibition
Negative control No inhibition No inhibition No inhibition No inhibition No inhibition No inhibition

EC50 values for each antibody tested at the concentration (μg/ml) at which 50% of the infection is neutralised. > 0.08*: The EC50 value could not be determined or extrapolated, due to maximal inhibition (close to 100%) maintained at the lowest tested concentration (0.08μg/ml). Shaded cells: More than 50% inhibition was observed even at the highest dilution.

What is antibody phage display?

The phage display technology encompasses the determination of interaction partners of a specific protein (protein-protein, protein-DNA, or protein-peptide). These interactions can subsequently be used as “bait” to capture phages displaying peptides, proteins, or antibodies encoded in high diversity DNA libraries. Through the interactions, it becomes possible to determine the function of a specific peptide or protein.

Phage display cycle: phage display library, panning/biopanning and validation by ELISA

The phage display technique commonly employs filamentous phages such as phage M13 from Escherichia coli. This method has proven to be a powerful way to interrogate libraries containing billions of different proteins or peptides.

The application of phage display on large antibody libraries has led to real success in the isolation of highly selective and specific monoclonal antibodies.

The use of libraries composed of billions of antibodies displayed on phages offers a highly valuable and effective alternative to traditional methods of antibody generation by allowing the quick selection of the most relevant candidates for your research.

M13 bacteriophage in antibody phage display

All ProteoGenix’s antibody phage display libraries are made using the filamentous phage M13, a virus infecting the bacterium E. coli. M13 is a lysogenic phage, comprised of a circular and single-stranded DNA encased in a thin flexible tube coated by about 2700 copies of protein pVIII, the major coat protein, and about 5 copies of pIII, the minor coat protein, present at the ends of the tube.

Infection with M13 plasmids is not lethal for bacteria and they are used for many recombinant DNA processes. Antibodies are generally displayed as fragments such as single-chain variable fragments (scFv), antigen-binding fragments (Fab), or variable heavy-chain antibody fragments (VHH or nanobodies).

These fragments are typically fused to protein pIII and cloned into a phagemid vector, comprising a simplified version of phage M13 containing only the pIII-antibody fusion protein, an origin of replication, and a selection marker (e.g., antibody resistance gene).

The phagemid vector is used in conjugation with a helper phage which, in turn, contains all essential elements of phage M13 except for a slightly defective origin of replication and no antibody fragments. The co-transformation of these two elements in E. coli results in the expression of hybrid phage particles generally displaying a single pIII-antibody fusion protein alongside native pIII proteins (essential for infection).

The reduced abundance of antibodies displayed per phage particle ensures only the binders with the highest affinity are selected during the process of biopanning.

Advantages of antibody phage display

The key attribute of phage display is the physical coupling between genotype and phenotype where the phage displays an antibody fragment on its surface while encoding the corresponding gene in its genome. This allows the fast enrichment of antigen-specific binders and amplification in their corresponding host. The major advantage of the technique lies in the simplified structure, stability, versatility, and reliability of phages which can be adapted to various surfaces or even used for in vivo applications.

Other advantages of phage display include:

  • Compatibility with toxic or non-immunogenic antigens (which cannot be used in hybridoma-based antibody discovery)
  • Ability to easily tailor antibody cross-reactivity, particularly useful when designing highly selective therapeutic or diagnostic applications (narrow cross-reactivity), or when developing complex envenoming therapies to target several closely related proteins venoms (wide cross-reactivity)
  • Easy and quick access to antibody sequences
  • When naïve high-diversity libraries are used, additional advantages include:
    • Reduced lead times (less than 7 weeks)
    • Minimization of animal use (no animal immunization is necessary)
    • Possibility of using the same antibody library in different projects (versatility)
    • Possibility of quickly generating oligoclonal therapies (antibody cocktails), invaluable in the fight against infectious diseases

What are the applications of antibody phage display?

Phage display comprises the study of protein-ligand interactions. For this reason, its applications are broad. When antibodies are displayed on the surface of phages, the process of selection can be used to:

Other advantages of phage display include:

  • Discover novel antibody functions (antibody discovery) with multiple applications including therapeutic, diagnostic, research, or catalytic antibody discovery
  • Engineer existing antibodies to increase their affinity towards a specific target and/or improve their biophysical properties and thus their developability

Moreover, peptides can be displayed on the surface of phages and screened against a specific antibody. In this way, phage display can be used for epitope mapping applications. This is invaluable for the further development of highly selective therapeutic applications, such as oligoclonal therapies, or diagnostic applications, such as Sandwich ELISA which requires the use of an antibody pair targeting non-overlapping epitopes of a specific antigen.

For additional resources, check all Frequently Asked Questions (FAQs) about phage display on our dedicated page.