Bacterial Strains
Cell Origins provides the most commonly used
E. coli strains used in both bacteriophage and phagemid-based phage display technology.
The filamentous bacteriophage viruses (M13, fd, and f1) infect gram-negative bacteria. Of these,
Escherichia coli (E. coli) is the most commonly used in phage display technology. The filamentous bacteriophages infect E. coli by binding via coat protein III to the F-pilus of the bacterial cell. When the F-pilus comes into contact with pIII, the pilus retracts, allowing the genetic material of the phage to be delivered into the host cell. The fd and M13 species of bacteriophages share similar biology; they both release viral progeny through the plasma membrane of
E. coli without causing cell lysis. This characteristic makes it easy to propagate filamentous bacteriophages in the lab, making them highly suitable for various phage display selection techniques.
Phage Display Using Bacteriophage Vectors
The bacteriophage vectors encode a modified version of the full phage genome that contains an antibiotic selection gene, as well as a recombinant gene encoding the foreign peptide or antibody fused to one of the coat proteins. The large size of antibodies and antibody fragments impairs the infection of E. coli and thus often leaves bacteriophage vectors unsuitable for the display of this type of ligands. However, bacteriophage vectors have been used successfully numerous times for peptide phage display on various coat proteins. Bacteriophage vectors do not require the use of helper phages for the propagation of viral particles since the phage genome contains all of the necessary genes for replication.
Phagemid-Based Phage Display
Phagemids are plasmids that contain the phage and bacterial origins of replication, and an antibiotic selection gene. Phagemids do not contain most of the wild-type genes of the filamentous phage. However, they typically encode a hybrid coat protein fused to a foreign antibody or peptide. Phagemid vectors can independently replicate in E. coli; however, they require a helper phage for the production of phage particles. The helper phage contains essential genes necessary for the assembly and release of phage clones. The smaller size of phagemid DNA enables easy transformation of E. coli, which directly relates to the diversity of the phage display library, and is, therefore, one of the most important considerations when choosing a phage display vector.
Related Products
The Vectors That Built Phage Display
In phage display technology, vectors are invaluable tools for introducing foreign genetic material into host cells, facilitating the propagation of DNA molecules, and for the production of phage virions.
Years prior to pioneering phage display technology. Dr. George P. Smith developed bacteriophage cloning vectors. Since then, the vectors have been utilized to create numerous phage display libraries of both peptides and antibodies.
Cell Origins carries the original bacteriophage vectors created by Dr. George Smith. We also offer customized bacteriophage and phagemid vectors with built-in tagging and analysis options to streamline your phage display procedures.
Premade and Customized Phage Display Libraries
At Cell Origins, we understand that peptide and antibody discovery can be a challenge. To help overcome these challenges, we are dedicated to providing high-quality phage display libraries that are rigorously controlled to obtain the lowest rate of stop codons and other unintended sequences. We offer newly created libraries of validated high quality and diversity, as well as access to the original libraries by Nobel prize winner, Dr. George Smith.
Our custom libraries are made with built-in options for post-selection analysis such as biotinylation, expression of soluble ligands, affinity isolation, and more. This allows you to get the most out of your peptide or antibody phage display library and get the best results. Our experts are here to help you every step of the way, ensuring that you get the most optimal phage display library for your needs.
Easy Production of Phage Particles
Coming soon! Helper phage are required to produce phage particles when using phagemid-based vectors. Cell Origins provides helper phage and detailed protocols for straightforward amplification of phagemid peptide and antibody libraries and the production of phage particles in E. coli.
Tailored Affinity Selections for Unique Project Needs
At Cell Origins, we understand that each project is unique and requires customized protocols to meet its individual needs. We're at the forefront of utilizing phage display technology to provide exceptional biopanning services for peptide and antibody discovery.
Our customized protocols are designed to meet the unique needs of each project. We offer tailored affinity selections that begin with gaining in-depth knowledge of each target molecule or tissue to design a customized phage display biopanning protocol based on our unique multi-tiered approach. Our strategies yield proven results both in vitro and in vivo, ensuring that our clients receive quality solutions to unlock their drug discovery projects.
Advanced Peptide and Antibody Screening
Biomolecular interactions among proteins, nucleic acids, carbohydrates, and lipids play a crucial role in biological processes. However, accurately capturing these interactions in the lab is challenging and can lead to misidentification and failure to identify hit molecules. At Cell Origins, we overcome these challenges by developing customized in vitro, in situ, or in vivo protocols for each screening procedure, ensuring the identification of the best peptides and antibodies.
At Cell Origins, we also employ our own novel approach to high-throughput screening of phage-displayed peptides and antibodies. Our novel method guarantees rapid production and purification of phage particles followed by unique biomolecular interaction analysis with 10-100x increased sensitivity compared to conventional methods.