The cell-based phage display technique uses intact cells as targets to identify functionally binding molecules through the display of external proteins or peptides fused with phage coat proteins on their surface. This screening platform is widely used in antibody discovery, peptide drug screening, protein interaction studies, and the discovery of cancer-targeting molecules. If you want to develop truly effective research tools, you must address the target in its natural habitat: on the surface of a living cell. Membrane proteins exist within intricate biological systems where both their shape and functional state depend on their natural physiological context. Creative Biolabs' in vitro cell-based phage display screening platform is explicitly designed to meet this challenge. Our screening platform uses live cells as targets, which allows you to find antibodies and peptides that bind to cell-surface proteins in their natural functional state.
At the heart of our Phage Display Screening Platforms is the powerful phage display technology. This method creates a direct physical connection between a protein (the phenotype) and its encoding gene (the genotype). We employ M13 phage display systems, which are filamentous bacteriophages that serve as versatile scaffolds for discovery and biotechnological applications. The core concept involves fusing the gene for a peptide or an antibody fragment to a phage coat protein gene. During phage assembly, this fusion protein is presented on the phage's exterior, ready to interact with a target, while its genetic code remains securely inside the phage particle. This direct linkage is what makes phage display technology a game-changer for antibody discovery and peptide discovery. It allows us to perform phage display library screening using libraries that contain billions of unique protein variants. We can pan these vast libraries against a target and isolate the rare phages that bind, then amplify them and sequence their DNA to identify the successful binder. This entire discovery process can be performed in vitro, offering a high degree of control and flexibility. While cell-based phage display screening is unparalleled for discovering binders in a complex biological context, isolating binders to a specific, purified molecular component is best achieved with our dedicated In Vitro Protein-Based Screening Platform.
Screening against whole cells is fundamentally different from panning on a single purified protein. The cell surface is a crowded and complex landscape, presenting unique challenges that, when properly navigated, yield uniquely valuable results.
Our in vitro biopanning protocol is meticulously adapted to maintain cell viability while achieving stringent selection.
Fig.1 The workflow for in vitro phage display.1
The complexity of the cell surface demands sophisticated strategies to isolate binders that are not just strong, but also exquisitely specific.
This is where cell-based phage display screening truly works. To ensure binders are specific to your target of interest and not just to common cell-surface proteins, we employ rigorous negative selection phage display protocols.
For the highest level of precision, we can integrate phage display flow cytometry. In this technique, cells are incubated with the phage library and then stained with a fluorescent antibody against the phage. A flow sorter then physically isolates the individual cells that show the highest fluorescence, meaning they have the most or the strongest binders attached. This method allows us to:
We utilize NGS phage display to gain a comprehensive, quantitative understanding of the selection process. By sequencing millions of clones from each round and from both positive and negative cell lines, phage display deep sequencing allows our bioinformaticians to:
While in vivo phage display in animal models has its place, it is a complex and resource-intensive method. For most therapeutic and diagnostic discovery programs, our in vitro cell-based phage display offers a superior combination of relevance and control:
Our in vitro cell-based screening service is a powerful engine for innovation, directly supporting cutting-edge research.
Achieving success with a cell-based screening project requires a comprehensive, synergistic, and specialized understanding of phage display, cell biology, and bioinformatics. We have it, and we apply it to every project. We design and tailor screening campaigns to bring you functional, specific, and actionable candidates. and discover how our cell-based screening platform can help advance your next breakthrough.
Can I provide my own engineered cell line for the screening?
Absolutely. We strongly encourage you to provide your specific cell line, whether it's an overexpressing, knockout, or patient-derived model. Our platform is highly adaptable. We will first work with you to validate the cell line's viability and target expression, ensuring it is robust enough for the biopanning process. This will enable us to optimize the protocol specifically for your system.
How do you ensure the binders are specific to my target protein and not just other random molecules on the cell surface?
Specificity is paramount in our process. We employ rigorous subtractive screening strategies before the main selection process. The phage library is first incubated with parental cells or other control cell lines that lack your target. This critical step effectively removes non-specific binders and enriches for clones that are highly specific to your unique cell surface protein of interest.
What if my target protein has very low expression on the cell surface?
This is a common challenge we are well-equipped to handle. We can employ more sensitive enrichment strategies, including increasing the number of screening rounds or using specialized amplification protocols. Additionally, our deep sequencing (NGS) analysis is powerful enough to detect and statistically validate rare binding events that would be missed by conventional methods, ensuring we can still identify promising candidates.
How will I be kept updated on the progress of my project?
Communication is key to our partnership. You will be assigned a dedicated Ph.D.-level project manager who serves as your single point of contact. We provide regular progress reports at key milestones, complete with data summaries and expert analysis. We are always available to schedule teleconferences to discuss results and strategize on the next steps, ensuring complete transparency throughout the project.
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Please kindly note that our services can only be used to support research purposes (Not for clinical use).
Creative Biolabs is a globally recognized phage company. Creative Biolabs is committed to providing researchers with the most reliable service and the most competitive price.
