Complement-Dependent Cytotoxicity (CDC) Assay

Complement-Dependent Cytotoxicity (CDC) Assay 2018-06-05T01:49:17+00:00
  • Help predict the potential magnitude of complement-mediated target lysis conferred by your therapeutic antibody with iQ’s complement-dependent cytotoxicity (CDC) assay
  • Personalized experimental design to ensure the most relevant CDC inhibition data (IC50s) are generated with your molecules
  • All assays are performed with high-quality reagents and strict controls by experienced immunologists
  • Data is provided in appropriate formats, including PowerPoint slides and/or direct data files
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Service Overview

About the CDC Assay

Complement-dependent cytotoxicity (CDC) is one mechanism by which therapeutic antibodies can exert specific target cell lysis through activation of an organism’s complement system. At iQ Biosciences, we routinely perform CDC assays and can help you design and execute experiments to ascertain the answers you seek.

CDC works by recruiting complement components in the serum to cells that are opsonized by antibodies. This effector function is mediated by the Fc region of the antibody in conjunction with the organism’s complement system, which consists of over twenty regulated proteins. Once recruited to the target cell, the complement components undergo multiple enzyme activation and cleavage events that lead to lysis of the antibody-bound cell. Drug development groups have taken into consideration the importance of having CDC function by making chimeric antibodies with specific isotypes (IgG3 > IgG1 >>> IgG2 ≈ IgG4) or engineering specific amino acid substitutions into either the hinge region or CH2 domain to improve CDC activity.

Lab-Tested, Immunologist-Approved

At iQ, we’ve refined protocols with quality-controlled complement sources (human, non-rodent, rodent) that can be used for product characterization or therapeutic candidate screening purposes as described in ICH guideline Q6B – Specifications: Test Procedures and Acceptance Criteria for Biotechnological/Biological Products (2.1.2 Biological Activity).

In addition, we will work with you to design and execute an experimental setup tailored to your goals. We will discuss important parameters, such as the type of serum used, antibody-to-target ratio, and optimal target cell lines- whether they are your own proprietary cell line(s) and/or human/mouse cell line(s) from our cell bank.

Figure A. Percent viability of target cell line treated with Test Article. The percentage of live target cells after treatment with increasing concentrations of the Test Article (green circles) or negative control article (blue squares) in the presence of human serum. Alamar blue was added after the treatment period and viability was measured with a spectrophotometer. The spectrophotometer reading is directly proportional to the number of live target cells, allowing the calculation of percent viability.

Our goal is to provide the most robust and consistent approaches to obtain meaningful results for you. Together, we will design assays and analyze data to functionally characterize your antibody for bioactivity and/or guide preclinical transition from in-vitro to in-vivo studies.

The iQ Experience

Tailored Experiments

Your research is important to us. Our scientists will work through each step of the process with you, including assay design, data analysis, and recommendations for future studies.

Streamlined Process

Simplify your workflow. Bypass the middle-man: at iQ Biosciences, you'll get immediate access to our biospecimen inventory, saving you both valuable time and money.


We're experts- so you don't have to be. Augmenting years of experience in immunology and working with immune assays, our scientists stay current with the latest publications and technology.

Exceptional Service

We're here to help. We know the challenges you're facing: whether it be through expedited service or our complimentary consulting services, our team is dedicated to helping you reach your goals.

Order Information


At iQ Biosciences, we understand that each client is unique. Upon quote request, we will provide complimentary consulting services to determine how to tailor our services to best meet your goals. Based on this preliminary assessment, we will be able to provide a price quote.

Expected Timetable

Fit a timetable appropriate to your research goals. We work with you to determine your expected turn-around on a case-by-case basis and ensure that our services fit your needs. Some experiments may require an expedited service – please inquire for more information.