Advanced Intrabody Discovery Service

Background Platform Service Portfolio Application Advantage FAQ Online Inquiry

Most of the human proteome resides within the cell, including a wealth of high-value targets for therapeutic intervention and research that remain inaccessible to conventional antibodies. Creative Biolabs has been at the forefront of antibody engineering, and we are proud to offer our industry-leading Intrabody Discovery Services, a comprehensive platform designed to break through the cell membrane barrier and empower researchers to modulate intracellular targets with the specificity and affinity of an antibody. Our integrated workflow combines diverse library construction, advanced screening technologies, and meticulous optimization to deliver functional intrabodies tailored to your unique project goals.

Discuss Your Project Today

What Are Intrabodies?

An intrabody is a recombinant antibody fragment, most commonly a Single-chain Variable Fragment (scFv) or a single-domain antibody (V_HH), that is genetically encoded and expressed inside a target cell. Unlike traditional monoclonal antibodies that function extracellularly, intrabodies are designed to fold correctly and bind to their specific antigen within the complex and reducing environment of the cytoplasm, nucleus, or other organelles. This unique capability makes them powerful tools for both basic research and therapeutic development.

Table 1. Comparison of Common Intrabody Formats

Feature	Single-chain Variable Fragment (scFv)	Dingle Domain Antibody ( V_HH)
Structure	Comprises the variable heavy (VH) and variable light (VL) chains of an antibody, joined by a flexible peptide linker.	A single monomeric variable antibody domain derived from heavy-chain-only antibodies found in camelids.
Size	~25-30 kDa	~12-15 kDa
Advantages	Utilizes conventional antibody frameworks; extensive research base.	Smaller size allows for better tissue penetration and access to cryptic epitopes; exceptional stability and solubility.
Ideal For	Applications requiring the classic antigen-binding pocket structure.	Probes for super-resolution microscopy, targeting small cavities on proteins, high-stability applications.

At Creative Biolabs, our platform is optimized for the discovery and development of both scFv and V_HH intrabodies, ensuring we can select the ideal format for your specific intracellular target.

Fig. 1 Summary of promising intrabodies are depicted underlining their potential for preclinical research and clinical application. (OA Literature). Fig. 1 Intrabodies as intracellular modulators.¹

Creative Biolabs' Super™ Intrabody Discovery Platform

Our end-to-end intrabody discovery platform is a fusion of cutting-edge technologies and deep-seated expertise. We guide your project from antigen design to the delivery of fully validated, expression-ready intrabody constructs.

Step 1: Antigen & Strategy Design

Target analysis and epitope prediction.
Recombinant protein expression or peptide synthesis.
Selection of intrabody format (scFv/ V_HH) and discovery strategy.

Step 2: High-Diversity Library Construction

Construction of immune libraries (from immunized camelids or rodents).
Generation of large naïve or synthetic human antibody libraries.
Diversity capacity exceeding 10¹⁰, ensuring broad epitope coverage.

Step 3: Advanced Intrabody Screening & Selection

Phage Display: A robust, classic method for panning high-affinity binders.
Yeast Display: Eukaryotic display system ideal for screening folded proteins and allowing for direct affinity measurement via FACS.
Intracellular Screening Systems: Proprietary methods like Yeast Two-Hybrid (Y2H) and Mammalian Protein-Protein Interaction Trap (MAPPIT) to select for clones that function directly within a cellular context.

Step 4: Intracellular Stability & Functionality Engineering

Sequence optimization for robust expression in mammalian cells.
Engineering for enhanced stability in the reducing cytoplasmic environment.
Fusion with localization signals (e.g., NLS for nuclear, MTS for mitochondrial) or effector domains (e.g., E3 ligase components for degradation).

Step 5: Comprehensive Characterization & Validation

Affinity and kinetics measurement (SPR/BLI).
In-cell expression confirmation via Western Blot or immunofluorescence.
Functional validation (e.g., co-immunoprecipitation, target knockdown confirmation, cell-based functional assay

Creative Biolabs' Comprehensive Intrabody Discovery Services Portfolio

We offer a flexible suite of services that can be tailored into a custom package to meet your precise research needs.

Service Category	Description	Key Deliverables
Custom Intrabody Library Construction	Generation of high-diversity phage or yeast display libraries from immunized animals or naïve/synthetic sources.	High-diversity antibody library; Quality control report.
High-Throughput Intrabody Screening	Screening of our pre-made or your custom libraries against your target protein to isolate specific binders.	List of unique antibody sequences (hits); Binding data for top candidates.
Intrabodies for Targeted Protein Degradation (TPD)	Discovery and engineering of intrabodies (degraders) fused to E3 ligase domains to induce proteasomal degradation of target proteins.	Validated intrabody-degrader constructs; Data demonstrating target knockdown.
Intrabody Characterization & Validation	Full biophysical and cellular characterization of lead intrabody candidates, including affinity, specificity, and in-cell functional validation.	Comprehensive characterization report; Validated lead intrabody clones.
Intrabody Expression Vector & Cell Line Services	Cloning of intrabody sequences into various expression vectors (e.g., lentiviral, AAV) and generation of stable cell lines for your downstream research.	Expression-ready plasmids; Stably expressing cell lines.

Applications: Unlocking New Biological Frontiers with Intrabodies

Our custom intrabody discovery services provide powerful reagents for a wide array of applications, enabling research that was previously impossible.

Target Validation and Functional Genomics: Directly modulate the function of an intracellular protein (inhibition, stabilization, or degradation) to elucidate its role in complex biological pathways. This provides a specific, reversible alternative to genetic knockout.
Targeted Protein Degradation (TPD): Engineer "degrader" intrabodies that recruit the cell's own ubiquitin-proteasome machinery to specifically eliminate a target protein of interest. This is a highly sought-after strategy for targeting "undruggable" proteins like transcription factors and scaffolding proteins.
In Vivo Imaging and Biosensors: Fuse intrabodies to fluorescent proteins (e.g., GFP) to visualize the localization, trafficking, and dynamics of endogenous proteins in living cells without the need for tags or overexpression.
Modulation of Signal Transduction: Block protein-protein interactions, sequester proteins in specific cellular compartments, or stabilize certain protein conformations to dissect and control cellular signaling cascades with exquisite precision.
Therapeutic Development: Intrabodies delivered via gene therapy vectors (e.g., AAV) hold immense promise for treating a range of diseases, including neurodegenerative disorders, cancers, and viral infections, by neutralizing pathogenic intracellular proteins.

Why Partner with Creative Biolabs for Your Intrabody Discovery Project?

Unmatched Expertise: With over 20 years dedicated to antibody engineering, our scientific team possesses the deep knowledge required to overcome the unique challenges of intrabody development.
Technology Leadership: We continuously invest in the latest platforms, from advanced display technologies to innovative intracellular screening systems, ensuring the highest probability of success.
End-to-End Solution: We offer a seamless, one-stop service from initial strategy to the delivery of fully validated, functional intrabodies, saving you time and resources.
Focus on Functionality: Our process goes beyond simple binding. We prioritize the selection and engineering of clones that demonstrate robust stability and function inside the cell.
Collaborative Partnership: We work as an extension of your team, providing transparent communication, expert consultation, and flexible solutions tailored to your specific scientific goals.

Contact Us Today for a Free Quote!

Frequently Asked Questions (FAQs)

Q: What is the primary difference between a conventional antibody and an intrabody?

A: The fundamental difference lies in their site of action. Conventional monoclonal antibodies (mAbs) are large IgG molecules that function outside the cell, binding to cell surface receptors or soluble antigens in the bloodstream. Intrabodies, in contrast, are smaller antibody fragments (scFv or V_HH) that are designed to be expressed inside a cell. This allows them to bind to and modulate the function of intracellular proteins, which constitute most potential drug targets and are inaccessible to traditional antibodies.

Q: How do you ensure that the selected intrabody will be stable and functional inside a cell?

A: This is the most critical challenge in intrabody development and a core strength of our platform. Simple in vitro binding (like ELISA) does not guarantee in-cell function. We address this through:

Contextual Screening: We employ specialized screening systems like Yeast Two-Hybrid (Y2H) or Mammalian Protein-Protein Interaction Trap (MAPPIT) that select for antibody fragments that can successfully fold and bind to their target within a living cell.
Sequence Engineering: Our experts analyze lead candidates and perform rational sequence optimization to improve stability and expression within the reducing environment of the cytoplasm, mitigating issues like aggregation or misfolding.
Rigorous Validation: Every lead intrabody undergoes validation in relevant mammalian cell lines to confirm intracellular expression and target engagement through methods like co-immunoprecipitation or immunofluorescence.

Q: Can you target proteins in specific subcellular compartments, like the nucleus or mitochondria?

A: Absolutely. This is a key feature of intrabody technology. We can genetically fuse our validated intrabody sequences with specific Subcellular Localization Signals (SLSs). For example, by adding a Nuclear Localization Signal (NLS), we can direct the intrabody to the nucleus to target a transcription factor. Similarly, a Mitochondrial Targeting Signal (MTS) can traffic the intrabody to the mitochondria. This allows for highly precise spatial control over target modulation.

Q: What starting material do I need to provide for an intrabody discovery project?

A: We are highly flexible and can start a project with various materials. The ideal starting point is a high-purity recombinant target protein (typically >100 µg). However, we can also work with:

The amino acid or cDNA sequence of your target (our team can manage the antigen production).
Specific domains or peptides of the target protein.
Even just the name and accession number of the target for an initial project consultation.

Q: What is the typical timeline for a standard intrabody discovery project?

A: While the exact timeline can vary depending on the project's complexity and scope, a standard end-to-end project—from library construction and screening to the delivery of validated lead intrabody candidates—typically takes between 12 and 20 weeks. We provide a detailed project timeline with clear milestones at the proposal stage.

Q: Which format is better for my project: scFv or V_HH?

A: The choice depends on the specific target and downstream application. V_HH are often favored for their small size, exceptional stability, and ability to bind unique "cryptic" epitopes that larger fragments might miss. scFvs are a more classic format, and vast libraries are readily available. Our scientific team will consult with you to analyze your target and project goals, recommending the optimal format and discovery strategy to maximize the probability of success.

Reference

Wagner, Teresa R., and Ulrich Rothbauer. "Single domain antibodies right in the middle: intrabodies as toolbox to visualize and modulate antigens in the living cell." Biomolecules 10.12 (2020): 1701. Distributed under Open Access license CC BY 4.0, without modification. https://doi.org/10.3390/biom10121701

×

Online Inquiry

All listed services and products are For Research Use Only. Do Not use in any diagnostic or therapeutic applications.