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C1q Binding Assay Services

C1q binding

The complement system is a mechanism used by antibodies to eliminate pathogens and cancer cells in the body. It is a collection of small proteins in the blood that usually circulate as inactive precursors. C1q is the first part of the classical complement pathway. IgG1, IgG2, IgG3 and IgM can fix complement and initiate the classical pathway. However, the activation of the complement cascade is strictly controlled and only occurs when the antibody binds to its antigen. The C1q binding assay highlights the activation of the C1 complex (consisting of a single C1q molecule and two C1r and C1s molecules), which occurs when C1q binds to multiple immunoglobulin (IgG) molecules complexed with an antigen.

Overcoming the challenges of antibody drug development

C1q Binding Assay Services

Creative Biolabs provides additional C1q binding assays to support the production, process development, characterization and similarity studies of therapeutic antibodies and Fc fusion proteins. Our scientists work with you to apply the C1q binding assay method that has been qualified by commercially available therapeutic monoclonal antibodies to demonstrate performance, and can specifically verify or qualify for your products.

Our offer includes:

Both methods can be used to demonstrate binding or lack binding for all types of therapeutic biobetter antibodies or biosimilars.

Sample Data

C1q Binding Assay Services

Fig.1 C1q binding assay.

C1q Binding Assay Services

C1q Binding Assay Services

Fig.2 C1q binding assay. Various concentrations of antibodies were added to 96-well plates coated with human C1q protein. Binding assay was detected with HRP-conjugated goat anti-human IgG; the binding activity was measured as absorbance at 450 nm.

Collaboration with Creative Biolabs

Creative Biolabs conducts bioassays on behalf of clients, either as a standalone project or as part of a larger development project. We focus on developing the right bioassays to help you understand the molecule and help guide you correctly. With extensive experience in Fc characterization, our team can work on custom solutions to meet the unique requirements of each product. With flexible global capabilities, you can provide services where you need it most.

Contact our expert scientists today to discuss how our range of Fc analytical services can improve your unique process.

Complement Research Tools


Creative Biolabs provides luciferase-based ADCC assay. This Jurkat cell based assay is pioneered by Creative Biolabs, and the methodology is very well accepted by the field. See attached ADCC Reporter Assay Protocol for further details. 

All products and services are for Research Use Only. Do Not use in humans.


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Creative Biolabs has established a team of customer support scientists ready to discuss ADCC/CDC optimization strategies, antibody production, bioinformatics analysis and other molecular biology/biotechnology issues.

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