Services
Providing Advanced Biological Technical Services for Researchers in Fundamental Science
Co-Immunoprecipitation (Co-IP) Service
Service Overview
Co-Immunoprecipitation (Co-IP) is a classical and widely applied technique for analyzing protein-protein interactions under near-physiological conditions. Based on the specific affinity between antibodies and antigens, Co-IP enables the isolation of protein complexes from complex lysates, providing essential insights into cellular signaling pathways, functional protein assemblies, and post-translational modifications.
At ProNet Biotech, we offer Co-IP services using transient expression systems in both plant and mammalian cells. Combined with Western blot or mass spectrometry detection, our Co-IP platform is well-suited for validating protein interactions discovered through other methods, such as yeast two-hybrid (Y2H) or GST pull-down assays.
Technical Principle
Co-IP uses an antibody that specifically binds to a target protein (“bait”) in a cell or plant lysate. If the bait protein forms a complex with one or more “prey” proteins, these interaction partners will co-precipitate with the bait during the immunoprecipitation step using Protein A/G beads. The complex is then washed, eluted, and analyzed via Western blot or mass spectrometry (MS).
Unlike methods that rely on artificial overexpression or in vitro binding, Co-IP preserves protein complexes in their native cellular context, enabling detection of physiologically relevant interactions, including those dependent on post-translational modifications.
Technical Advantages
· Detects interactions in a native or near-native cellular environment
· Capable of identifying both known and novel binding partners
· Suitable for confirming endogenous and overexpressed protein interactions
· Compatible with both Western blot and LC-MS/MS detection
· Low false-positive rate compared to overexpression-based systems
· Optionally integrated with yeast two-hybrid or GST pull-down assays for multi-angle validation
Co-IP Suitable Applications
· Protein Interaction Detection: Co-IP is ideal for determining whether two target proteins interact within living cells.
· Protein Complex Isolation: This technique is suitable for isolating protein complexes that interact in their natural state, providing insights into the physiological roles of these complexes.
Experimental Workflow
1. Gene synthesis and vector construction
2. Transient expression in plants or mammalian cells
3. Protein extraction and expression verification
4. Immunoprecipitation using Protein A/G beads
5. Detection via Western blot or LC-MS/MS
Sample Requirements
Sample Type | Requirement | Shipping |
|---|---|---|
| Sequence for Sythesis | / | / |
Plasmid | >2 µg, with vector map and resistance info | Ice pack |
Bacterial Colonies | >500 µL, sterile & labeled | RT |
Tobacco Leaves | ≥3 infiltrated leaves | Dry ice |
Total Protein Lysate | >500 µL | Dry ice |
Antibody (IP grade) | >30 µL | Dry ice |
Transfected Mammalian Cells | ~3×10⁷ cells (~3×10 cm dishes) | Dry ice |
Cell Lysate with Bait/Prey | >5 mL | Dry ice |
Service Content and Deliverables
Service Content | Period (Working Days) | Deliverables |
|---|---|---|
Gene Optimization | 15 | 1. Gene synthesis report 3. Expression plasmid |
Identification of Transient Expression | 10 | 1. Expression verification report |
Co-IP Experiment | 7 | 1. Original data and resulting images |
Protein Interaction Experimental Relationships
Co-IP is a primary method for detecting protein-protein interactions, but it should be viewed in relation to other experimental techniques like yeast two-hybrid assays and GST pull-down assays.
- Yeast Two-Hybrid: This in vivo experiment helps verify potential protein interactions but can suffer from a higher false-positive rate. Therefore, further validation is often required.
- Co-IP: Co-IP offers a lower false-positive rate and allows the analysis of protein interactions in their natural state. It is particularly effective for isolating naturally interacting protein complexes.
- GST Pull-Down Assay: While Co-IP cannot determine whether the interaction is direct or indirect, the GST pull-down assay can be used to verify direct interactions by isolating the target protein in an in vitro setting.
Together, these methods offer a powerful combination for comprehensive protein interaction validation.
Frequently Asked Questions
Q1: Why do Co-IP and other methods (e.g., BiFC or Y2H) sometimes give different results?
A: Co-IP detects both direct and indirect interactions. If an interaction requires a third protein, it may appear in Co-IP but not in other binary systems like GST pull-down.
Q2: What is the difference between IP and Co-IP?
A: IP (Immunoprecipitation) isolates a single target protein using an antibody. Co-IP captures interacting partners bound to the target protein, enabling the study of protein complexes.
Case Studies
High Transformation Efficiency: We consistently achieve high transformation efficiency, ensuring reliable and reproducible results.
Authentic Data and High-Quality Images: Results include control groups, real data, and aesthetically pleasing images that clearly demonstrate protein interactions.
Why Choose ProNet Biotech?
Expertise: Dedicated molecular interaction team with 10+ years of experience.
One-stop services: Data-rich reporting: High-resolution images + standardized documentation.
Data-rich reporting: High-resolution images + standardized documentation.
Global support: Fast communication, customizable workflows, and technical guidance.
Get in Touch
Ready to explore protein interactions in their native cellular context? Contact us today to learn how our Co-IP platform can support your next discovery.
Services Workflow
Online Consultation
01
Solution Matching
02
Service Contract
03
One-Stop-Services
04
Project Report
05
Related Products
Product Inquiry
Contact Us
Tel: +86 025-85205672
Email: info@pronetbio.com
Address: Building 3C, Nanjing Xianlin Zhigu,
Qixia District, Nanjing, Jiangsu, China, 210033
Need more information?
Let's connect!