What species do you use for in vivo phage display?

We primarily use mice (immunocompetent or immunodeficient), but can accommodate rats and custom transgenic models upon request.

Can you work with my custom phage library?

Yes, we support both premade and custom libraries. We'll work closely with you to assess the suitability of your construct for in vivo application.

How many rounds of selection are needed?

Most projects involve 3–5 rounds of in vivo biopanning, depending on tissue type and complexity.

Can you validate hits beyond peptide sequencing?

Absolutely. We offer peptide synthesis, ELISA validation, imaging, and flow cytometry upon request.

What if I don't know which tissue to target yet?

Our team can help design exploratory screens or combine in vivo with ex vivo approaches to identify biodistribution profiles across multiple organs.

In Vivo Phage Library Screening Services

Introduction Our Services Workflow Platform Deliverables Advantages Customer Review FAQ

Introduction

At Creative Biolabs, we specialize in unlocking the potential of in vivo phage display screening to accelerate your discovery of tissue-specific targeting peptides. Our team brings together decades of combined expertise in molecular biology, antibody engineering, and peptide screening technologies. We offer cutting-edge solutions tailored for researchers looking to identify homing peptides or novel ligand candidates that exhibit high affinity and selectivity in live animal models.

Phage display is a time-tested platform for discovering ligands, but traditional in vitro methods often fall short when it comes to biological relevance. That's where Creative Biolabs' in vivo screening platform stands apart. By allowing phages to circulate in live animals, we preserve the complex physiological barriers—vascular access, tissue penetration, enzymatic degradation, and immune surveillance—that influence targeting specificity in real-world conditions.

Our Services

At Creative Biolabs, our in vivo phage display screening services are designed to help you discover peptides that home to your tissue or disease model of interest with unmatched physiological relevance. Whether you are exploring drug delivery systems, biomarker discovery, or imaging agent development, we tailor each screening campaign to your project goals.

We provide customized identification of targeting peptides for different tissues and organs, including but not limited to:

Tumor targeting via in vivo phage display screening
Atherosclerosis plaque targeting
Vascular endothelium targeting, including BBB-penetrating ligands
Muscle tissue targeting, relevant for neuromuscular diseases, and delivery vehicles
Human synovium targeting, supporting translational research in arthritis and related diseases

Each service includes iterative in vivo biopanning, tissue harvest, and clone recovery to ensure enrichment of high-affinity, tissue-specific phage clones.

Workflow

Our streamlined workflow ensures high-quality results with clear deliverables:

Experimental Design

Collaborative project setup to align on animal model, tissue targets, and library selection.
Define dosing strategy, circulation time, and sample collection plan.
Ensure ethical compliance and optimized study design for translational relevance.

Library Injection

Systemic or local administration of phage library (e.g., tail vein, intraperitoneal).
Injection route and dosage are tailored to the tissue accessibility and project goals.
Libraries can include scFv, Fab, or peptide formats for flexible binder discovery.

Tissue Harvesting & Phage Recovery

Tissues/organs are collected post-circulation; phages bound to or internalized into target tissues are recovered.
Homogenization and washing steps remove unbound phages while preserving tissue-bound candidates.
Quantitative analysis performed to monitor biodistribution and enrichment efficiency.

Amplification & Enrichment

Recovered phages are amplified and subjected to further rounds of in vivo selection.
Each cycle increases the proportion of high-affinity, tissue-specific binders.
Enrichment quality is monitored via titering and phage DNA sequencing.

Phage Clone Characterization

Individual clones are sequenced, and top candidates are validated for specificity and binding.
Binding assays, immunohistochemistry, or biodistribution validation performed as needed.
Data-driven selection ensures only clones with true biological relevance are advanced.

Optional Peptide Synthesis/Validation

Functional assays, binding studies, or imaging with synthesized peptides as required.
Custom peptide labeling (e.g., biotin, fluorescent tags) available for visualization or tracking.
Enables downstream use in diagnostic or therapeutic applications.

Kick Off Your Screening—Request Pricing

Fig.1 Process of in vivo phage library screening. (Creative Biolabs Original). Fig.1 Workflow of in vivo phage library screening. (Creative Biolabs Original)

In Vivo Screening Platform

At Creative Biolabs, we've built a robust and adaptive in vivo phage display platform that empowers researchers to discover targeting ligands with true biological relevance. Our approach combines high-diversity peptide or antibody phage libraries with real-time systemic circulation in living models, enabling the identification of tissue-specific binders that engage with their targets under physiologically relevant conditions.

Our proprietary screening platform supports libraries with over 10⁹ unique clones, providing expansive coverage of potential binding motifs. These libraries are allowed to circulate through live animals, navigating vascular barriers and interacting with native cell surfaces across different organs. After defined circulation periods, we harvest target tissues and isolate phage clones that have selectively accumulated or internalized into those tissues. This natural selection process mimics the biodistribution of therapeutic agents and allows us to identify high-affinity ligands with in vivo functionality.

What truly sets Creative Biolabs' platform apart is the depth and specificity of the insights it generates. We frequently recover sequences that align with known receptors or protein families—ideal for repurposing as diagnostic ligands or delivery vectors. Additionally, we often uncover novel, uncharacterized peptides that bind to unknown or poorly annotated targets, opening new avenues for biomarker discovery and therapeutic innovation.

In addition to our flagship in vivo screening services, Creative Biolabs also offers complementary phage display screening formats:

Fig.2 Solid Screening. (Creative Biolabs AI).

Solid-phase Library Screening

Fig.3 Solution Screening. (Creative Biolabs AI).

Solution-phase Library Screening

Fig.4 Cell Screening. (Creative Biolabs AI).

Cell-based Library Screening

Fig.5 Protease Screening. (Creative Biolabs AI).

Protease Substrate Screening

Fig.6 In vivo Phage Display. (Creative Biolabs AI).

Ex vivo Phage Display Services

From functional assays to multi-target characterization, our comprehensive screening platform is engineered to identify and validate your most promising candidates. We provide the critical data you need to accelerate your discovery pipeline.

Your Perfect Solution Awaits – Request a Quote

Deliverables

Each project concludes with a detailed report that typically includes:

Experimental design summary and methodology
List of enriched peptide sequences with frequency data
Sanger or NGS results of selected clones
Raw data and titer curves from biopanning rounds
Functional annotation or bioinformatics insights (on request)
Optional peptide synthesis and in vitro validation

We are also happy to accommodate additional requests, such as peptide imaging agents or downstream conjugation.

Client Success Stories: Discovery of Novel Tissue-Specific Peptides via In Vivo Phage Display

We deployed our end-to-end in vivo screening platform, leveraging our proprietary, high-diversity phage display peptide library. The campaign was designed to maximize specificity and isolate high-affinity candidates.

Key Campaign Parameters

Library: Our proprietary, premade Phage Display Peptide Library, ensuring vast sequence diversity.
Animal Model: Female BALB/c mice (6-8 weeks old, n=3 per group).

Methodology

A key advantage of our platform is the inherent negative selection process. As the library circulates, phages that bind to ubiquitous plasma proteins and non-target cell surfaces are naturally cleared from the system, significantly reducing background noise and enriching for truly specific binders.
Phages that successfully homed to the target tissue were recovered, amplified, and subjected to subsequent rounds of selection to enrich for the most potent candidates.
The final enriched phage pool was analyzed by Next-Generation Sequencing (NGS) to identify the specific peptide sequences.

Significant Enrichment and Identification of Novel, Specific Binders

Cases	Target Tissue	Control (Counter-Selection) Tissues	Results & Outcome
Case 1	Target Tissue A	Kidney, Liver
Case 2	Target Tissue B	Liver, Spleen, Kidney

For both Target Tissue A and Target Tissue B, we demonstrated effective and significant enrichment of phage populations that selectively homed to the target organ over the control organs.
The subsequent NGS analysis revealed several families of novel peptide sequences unique to each target tissue.

These client-owned sequences represent high-value assets, providing:

High-Potential Candidates: A panel of validated peptides ready for the next stage of development as drug delivery vehicles or diagnostic agents.
Novel Biological Insights: The potential to identify previously unknown endothelial receptors or cell-surface proteins, opening doors to new drug targets.
Actionable Data: Clear, high-quality sequencing data that empowers confident decision-making for downstream R&D.

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Why Choose Creative Biolabs?

What sets Creative Biolabs apart is more than our technology—it's our commitment to scientific collaboration, transparency, and technical excellence. Here are a few reasons to partner with us:

Physiological Relevance

Our in vivo approach replicates complex tissue microenvironments for more biologically meaningful screening outcomes.

Broad Target Accessibility

We have experience with systemic, local, and organ-targeted administration across rodent and humanized models.

Customizable Design

Whether you want to screen a commercial peptide library or your own custom-built phage constructs, we adapt to your goals.

End-to-End Support

From study design to peptide validation, Creative Biolabs offers comprehensive, publication-ready support.

Start Your Project Today – Request a Quote

Customer Review

"Creative Biolabs' in vivo phage display service was a game changer for our oncology program. The peptides they helped us identify showed clear tumor enrichment in vivo, saving us months of screening and validation work. Their team was responsive, scientifically rigorous, and a true partner in discovery."— Dr. H. ReyXXXX, Principal Investigator, Cancer Biology Program

Partner with Creative Biolabs to elevate your research with our in vivo phage display screening. We're here to help accelerate your scientific goals. Contact us today to request a quote or schedule a consultation.

FAQ

Q: What species do you use for in vivo phage display?
A: We primarily use mice (immunocompetent or immunodeficient), but can accommodate rats and custom transgenic models upon request.
Q: Can you work with my custom phage library?
A: Yes, we support both premade and custom libraries. We'll work closely with you to assess the suitability of your construct for in vivo application.
Q: How many rounds of selection are needed?
A: Most projects involve 3–5 rounds of in vivo biopanning, depending on tissue type and complexity.
Q: Can you validate hits beyond peptide sequencing?
A: Absolutely. We offer peptide synthesis, ELISA validation, imaging, and flow cytometry upon request.
Q: What if I don't know which tissue to target yet?
A: Our team can help design exploratory screens or combine in vivo with ex vivo approaches to identify biodistribution profiles across multiple organs.