MtoZ Biolabs employs advanced instruments and analytical platforms to offer the Co-Immunoprecipitation (Co-IP) service which can be used to detect and verify protein-protein interactions. This service is suitable for protein function analysis, interaction network construction, and the confirmation of specific interaction relationships, providing stable and reliable data support for elucidating protein interaction patterns and biological associations.

What Is Co-Immunoprecipitation (Co-IP)?

Co-Immunoprecipitation (Co-IP) is a classical method that uses a specific antibody to capture a target protein together with its native interacting partners and verify protein interactions under near-physiological conditions. The principle involves the antibody binding to the target protein to form an immune complex, followed by enrichment and washing through protein A/G affinity matrices, enabling the detection of co-precipitated binding proteins. Co-IP can accurately reflect intracellular complex states and serves as an important approach for validating interaction relationships, analyzing regulatory features, and supporting functional studies.

Cai, Z T. et al. Expert Opinion on Drug Discovery, 2025.

Figure 1. The Standard Procedure for Co-IP.

Co-Immunoprecipitation (Co-IP) Service at MtoZ Biolabs

MtoZ Biolabs utilizes established Co-IP technology to provide protein interaction detection services for various sample types.

• Verify whether the target protein interacts specifically with a candidate protein
• Compare changes in interaction strength under different treatment conditions
• Distinguish specific interactions from nonspecific binding
• Support the identification and confirmation of key interaction pairs for downstream functional studies

Our analysis delivers clear and reliable insights into protein interaction states, enabling researchers to advance their studies with greater efficiency.

Workflow of Co-Immunoprecipitation (Co-IP) Service

1. Sample Collection and Preparation

• Endogenous interaction detection: Directly obtain cell or tissue samples and perform gentle lysis to maximally preserve the natural protein interaction state.
• Non-endogenous interaction detection: Use an exogenous expression system to produce tagged target proteins, ensuring sufficient expression levels and facilitating enrichment.

2. Antibody Selection

• Specific antibodies: Select antibodies with high specificity and affinity for the target protein to enable precise immunoprecipitation.
• Tag antibodies: Suitable for standardized detection of FLAG, HA, Myc, and other tagged proteins, improving experimental consistency.

3. Immunoprecipitation and Complex Capture

Incubate the antibody with the protein sample to form an antibody–target protein complex, and use a Protein A/G system to capture the associated interacting proteins.

4. Washing and Complex Elution

Use appropriate washing conditions to remove nonspecific components, followed by elution of true interaction complexes to provide clean samples for downstream detection.

5. Downstream Detection

Analyze the composition of the complexes using SDS-PAGE, Western blot, or high-resolution mass spectrometry to verify the presence of interactions and their relative changes.

6. Data Organization and Result Output

Integrate detection data and perform scientific interpretation to generate structured conclusions on protein interactions and a summary report.

Why Choose MtoZ Biolabs?

• High-specificity enrichment: Use high-affinity antibodies to precisely capture the target protein and its interaction partners.
• Authentic interaction state: Gentle handling preserves the natural binding state of proteins to the greatest extent.
• Multidimensional validation: Can be combined with WB or mass spectrometry for interaction confirmation, enhancing result reliability.
• Strong adaptability: Suitable for both endogenous and exogenous expression systems and supports multiple sample types.
• Customized experimental design: Precipitation conditions can be adjusted according to protein characteristics and research objectives.

Applications of Co-Immunoprecipitation (Co-IP) Service

1. Signal Pathway Analysis

Used to identify interaction relationships among key proteins within a pathway, helping to construct upstream and downstream regulatory networks and reveal mechanisms of signal transmission.

2. Mutation Effect Analysis

Compares binding differences between wild-type and mutant proteins to evaluate the impact of critical amino acid residues or domains on protein-protein interactions.

3. Protein Complex Composition Validation

Used to confirm whether the target protein participates in a specific complex and to analyze changes in complex assembly or dissociation under different conditions.

4. Cellular State Comparison

Used to monitor interactions during proliferation, differentiation, aging, or stress stimuli, helping to reveal functional changes of proteins under different physiological conditions.

5. Immune Regulation Analysis

Applicable to studying interactions among immune receptors, signaling factors, and inflammation-related proteins, helping to elucidate mechanisms of immune activation or immune suppression.

Deliverables

• Comprehensive Experimental Details
• Materials, Instruments, and Methods
• Protein Interaction Analysis Results
• Visualized Analysis Figures
• Raw Data Files
• Comprehensive Analysis Report

FAQ

Q1: What types of samples are suitable?

A1: Co-IP is suitable for protein samples with defined origin, preserved native conformation, and stable interaction characteristics, including endogenous proteins from cell or tissue lysates as well as recombinant proteins obtained through expression and purification. Samples should show no significant degradation or interfering components to ensure that interaction signals are authentic and reliable.

Q2: What is the service general workflow?

A2:

Q3: What data formats are provided?

A3: MtoZ Biolabs provides standardized data outputs, including:

• Original experimental images (Co-IP, SDS-PAGE, Western blot)
• Protein interaction result tables (Excel/CSV)
• Visualized analysis figures (PNG/TIFF)
• Comprehensive analysis report (PDF, including workflow, data interpretation, and key notes)

If special analytical requirements exist, data formats can be customized according to project specifications.

Q4: How should I prepare samples?

A4: To ensure accurate and reliable interaction results, we recommend:

• Sample purity: Avoid degradation, precipitation, and high-salt or strong detergent components that may disrupt interactions.
• Sample storage: Store at 4℃ for short-term use and -80℃ for long-term preservation, minimizing freeze-thaw cycles.
• Sample shipping: Use sealed low-temperature transport to maintain protein activity and structural stability.
• Additional information: Provide protein origin, tag information, concentration, and buffer system to support optimal experimental design.

For more information, please refer to Sample Submission Guidelines for Proteomics, Sample Submission Guidelines for Metabolomics.

Start Your Project with MtoZ Biolabs    

Contact us to discuss your experimental design or request a quote. Whether you are exploring new interaction relationships or evaluating the functional relevance of specific proteins, we can provide stable, reliable, and high-quality technical support for your research.