Whether you need ready-made naïve antibody libraries or a partner to develop high-diversity immune libraries for antibody phage display, ProteoGenix offers the market’s most extensive guarantees. Drawing from our experience in creating over 60 high diversity libraries (109 to 1010), our library generation process is designed to recover and optimize antibody repertoires from any host species (mouse, rabbit, camelid, human, etc.) and in any format (scFv, Fab, VHH) maximizing library diversity.

Our antibody phage display service process

Our antibody phage display service process

  • Choice of an adequate antigen format (protein, peptide, DNA, small molecules, or cells)
  • Antigen production
  • Conjugation to carriers (only for peptides or small molecules)

Host selection & immunization*

  • Choice of the most suitable host species and antibody format (scFv, Fab, or VHH)
  • Design of an efficient immunization strategy

*only for immune library generation

Cell harvesting

  • Harvesting and cell separation
  • Isolation of spleen, bone marrow, and peripheral blood mononuclear cells (PBMCs)

Antibody repertoire harvesting

  • mRNA isolation
  • cDNA synthesis
  • Amplification of antibody encoding genes with specific primers (Fv, Fab, or VHH regions)

Phagemid library construction

  • Randomized heavy and light chain pairing (only for Fab and scFv libraries)
  • Cloning of the antibody fragments (fused to M13’s minor coat protein G3P) into the phagemid vectors
  • Library QC

14-19 weeks

Library purchase
Buy our naïve or immune libraries to carry out phage display campaigns at your facilities

Phage display
Choose to perform your phage display panning campaigns with us

Naïve or immune antibody phage display libraries?

Antibody libraries can be generated from naïve hosts who have never been challenged with a specific immunogen or from immune hosts who have developed a strong and specific humoral response against the desired target. In comparison to other antibody generation approaches, antibody libraries have considerable advantages including:

  • Elimination of the need for animal immunization (naïve libraries only)
  • Elimination of the need for antibody humanization (fully human antibody libraries only
  • Compatibility with nonimmunogenic or toxic antigens (it is unnecessary to generate an immune response)
  • Faster turnaround times (a few weeks instead of months)

Naïve antibody libraries typically comprise the vast naïve (unchallenged) antibody repertoire of many individual hosts to maximize diversity and functionality. In contrast, immune antibody libraries are built from a reduced number of hosts and maximize the affinity of the antibody repertoire against a specific immunogen (require animal immunization).

Antibodies generated from naïve libraries may, at times, present lower affinity towards a specific target in comparison to antibodies generated from immune libraries. But the choice between the two library types can be a complex one. It depends on several factors including the desired timeline, available budget, and project’s goals.

Naïve libraries are uniquely adapted to projects requiring fast turnarounds or projects focused on developing antibodies against different antigens (i.e. development of antibody cocktail therapies, antivenom treatments, etc.). Moreover, naïve library construction is generally considered more time-consuming and labor-intensive, these libraries can serve a wide diversity of projects in comparison to immune libraries, which are restricted to a single antigen. However, for projects that prize antibody affinity, the development of immune antibody libraries should be preferred.

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 6-7 weeks 14-19 weeks + 6-7 weeks
Price + ++

What are the advantages of the phagemid system for antibody library construction?

Antibody libraries based on phagemid vectors have a critical advantage over full phage libraries – a higher transformation efficiency. Due to its “minimal” size, E. coli is more easily transformed by phagemid than by phage vectors. Moreover, since most resulting phage particles derived from phagemid libraries have only a single antibody fragment on its surface (monovalent), the selection of high-affinity antibodies is more efficient than when multivalent formats are used (phage vectors). In other words, the monovalent format ensures that antibodies with weak affinity can be easily washed off during panning campaigns.

However, because phagemid libraries need to be amplified by direct competition with a helper phage with wild-type G3P, the vast majority of the phages will be devoid of antibody fragments (“bald” phages”) but still retain their infectivity.

To circumvent this issue and reduce the abundance of “bald” phages, a trypsin cleavage site is often introduced into the wild-type G3P. This modification ensures that, after panning and enrichment of high-affinity antibody fragments, trypsin treatment can be performed to render “bald” phages non-infective. The same trypsin cleavage site is also added to the linker region between the antibody fragment and G3P, so that antibody fragments can be cleaved from positive phages to allow them to infect E. coli.

Trypsin cleavage of antibody phage display libraries
Adapted from Ledsgaard, L. et al. Basics of Antibody Phage Display Technology. Toxins. 2018; 10:236. doi:10.3390/toxins10060236