Antibody phage display services

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

“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.”

The phage display technology involves the determination of interaction partners of a protein (protein-protein, protein-DNA or protein-peptide interactions), which would be used as the “bait” for phages expressing peptides, proteins or antibodies coded by a huge DNA library (consisting of all coding sequences of a given organism). The function of that protein may therefore be determined.

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

The phage display technique uses the filamentous phage, a virus that lives on E. coli. This method has proven to be a powerful technique for the interrogation of libraries containing billions of different proteins or peptides.
The application of phage display on large antibody libraries has been a real success with regard to the isolation of monoclonal antibodies which are highly specific against an antigen.
These new methods, using libraries composed of billions of antibodies expressed on phages, offer highly valuable alternatives that have proven to be as effective as traditional methods in the generation of billions of components and their quick selection to identify the most interesting candidates for your research.

As such, phage display is a useful and state-of-the-art tool widely used in therapeutic antibody discovery.

The major advantage of phage display lies in the simplified structure, stability and therefore reliability of phages, making it possible to be applied to various surfaces but also to in vivo applications.
The main characteristic of the phage display technique is the physical coupling between genotype and phenotype (phage will « display » the protein on its outside while containing the gene for the protein inside). This requires the artificial introduction of encoding DNAs into phages, explaining the large diversity of phage-based antibody libraries. The engineered antibody fragments, which are generated by phage display at ProteoGenix, are single chain variable fragment format (scFv), Fab-based antibody format presentation and single-domain antibodies (VHH).

All ProteoGenix antibody phage display libraries are made of the M13 filamentous phage, a virus that infects the bacterium E. coli. This bacteriophage is the most commonly used for phage display and will be appropriate for you research.

M13 is a lysogenic filamentous phage, comprised of a circular and single-stranded DNA encased in a thin flexible tube made up of about 2700 copies of a single protein called 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.