Direct Cytotoxicity Assay
The expert immunologists at iQ Biosciences perform Direct Cytotoxicity Assays to evaluate the potency and specificity of therapeutic candidates, including antibodies and antibody-drug conjugates (ADCs). Using microplate reader-based and flow cytometry-based approaches, we assess cell viability, membrane integrity, and apoptosis to determine the direct cytotoxic effects of therapeutics on antigen-positive and antigen-negative cell lines. Our flexible assay designs support lead candidate screening, ADC optimization, and comparative efficacy assessments, generating high-quality data to guide preclinical development and therapeutic refinement.
Our services
- Measure direct cytotoxicity of therapeutic treatments, including antibody drug conjugates (ADCs), using microplate reader-based assays or flow cytometry-based methods.
- Compare EC50 and maximum response values across therapeutic candidates and benchmark treatments.
- Evaluate dose-dependent and time-dependent cytotoxic effects by selecting specific timepoints and therapeutic concentrations.
- Utilize cell lines or high-quality primary cells–including PBMCs or isolated cells–as target models.
- Deliver data in user-friendly formats such as PowerPoint, Excel, or GraphPad Prism for easy interpretation.
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.
Expertise
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.
Service overview
How can iQ Biosciences help achieve your goals the smarter way?
Many therapeutic antibodies are designed with effector function in mind, enabling Fc domain interactions with complement proteins and/or immune effector cells. However, antibodies can also function as agonists or antagonists, engaging or blocking receptors that regulate downstream signaling pathways related to cell viability. Through this mechanism, antibodies may induce direct cytotoxicity in target-expressing (“antigen positive”) cells. Additionally, antibody-drug conjugates (ADCs) can facilitate direct cytotoxicity by delivering a cytotoxic payload specifically to a target cell.
At iQ Biosciences, we provide direct cytotoxicity assays to evaluate therapeutic candidates. For a high-throughput and well-validated approach, CellTiter-Glo® can be used in a microplate reader-based assay to measure cell viability. Additional methods include CytoTox-ONE™ for assessing membrane integrity and flow cytometry-based approaches, such as intercalating and fixable viability dyes or Annexin V staining to evaluate apoptosis.
These methods help assess the potency and efficacy of your therapeutic candidates in comparison to relevant controls, such as free payload or small molecule, isotype control ADCs, unconjugated antibody (i.e. naked mAb), unconjugated isotype control, or therapeutic benchmarks. Testing on antigen-positive cell lines with varying antigen densities, as well as antigen-negative cell lines, can provide further insight on antibody specificity and efficacy. Additionally, we can validate cell lines or primary cells for target antigen expression, growth kinetics, or payload sensitivity to ensure assay suitability.
Applications for ADC therapeutics:
- Evaluate ADC cytotoxic efficacy during lead candidate screening.
- Optimize payload selection and ADC design to enhance therapeutic impact.
- Compare efficacy across different ADC constructs and payload-linker combinations.
- Confirm target specificity by assessing cytotoxic effects on antigen-positive versus antigen-negative cell lines.
A
B
Direct cytotoxicity of an ADC using antigen-positive target cells (A) and antigen-negative target cells (B). Target cell viability was measured after 5 days of incubation with a dose response of targeting antibody with payload (blue), isotype control antibody with payload (black), or payload alone (red). Both cell lines demonstrate susceptibility to small molecule (payload) cytotoxicity, but ADC cytotoxicity was observed on target-expressing cells only.
Order Information
Pricing
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.
