Cellular Cytotoxicity

Choosing the Right Method for CAR-T, CAR-NK and ADCC Research

Selecting the right immune cell-mediated cytotoxicity assay is essential for accurately evaluating CAR-T, CAR-NK, T-cell engager and antibody therapeutics.

Whether your priority is mechanistic insight, high-throughput screening or potency testing, choosing the appropriate assay format can significantly improve data quality and accelerate your research. 

This guide compares the three most widely used immune cell-mediated cytotoxicity assay formats to help you identify the best solution for your application.

Why Measure Immune Cell-Mediated Cytotoxicity?

Immune-mediated cytotoxicity measures the ability of immune effector cells to eliminate target cells. It is a key functional readout throughout immunotherapy research, enabling scientists to evaluate:

  • CAR-T and CAR-NK cell potency
  • Antibody-dependent cellular cytotoxicity (ADCC)
  • T-cell engager (BiTE) activity
  • PBMC-mediated target cell killing
  • Immune cell functionality during therapeutic development

By directly quantifying target cell death after co-culture with immune effector cells, researchers can compare therapeutic candidates, optimise experimental conditions and generate reliable functional data.

Compare the Main Cytotoxicity Assay Technologies

Assay Format Main Readout Key Advantages Best Applications Throughput Required Instrument
Flow Cytometry Dead target cells identified using CFSE/7-AAD staining Single-cell resolution, multiparametric analysis PBMC cytotoxicity, mechanistic studies Medium Flow cytometer
Luciferase-Based Luminescence proportional to viable target cells High sensitivity, quantitative, scalable CAR-T, CAR-NK, ADCC, potency assays High Luminescence microplate reader
LDH Release LDH enzyme released from damaged cells Label-free, simple workflow Routine cytotoxicity screening High Absorbance microplate reader

If your priority is... Recommended Assay
Investigating killing mechanisms Flow Cytometry
Single-cell analysis Flow Cytometry
Highest analytical sensitivity Luciferase-Based
High-throughput screening Luciferase-Based
CAR-T potency testing Luciferase-Based
CAR-NK functional assays Luciferase-Based / Flow Cytometry
Routine cytotoxicity screening LDH Release
Label-free detection LDH Release

Flow Cytometry-Based Cytotoxicity Assays

Flow cytometry remains the gold standard for researchers seeking detailed mechanistic insight into immune-mediated killing.

Target cells are labelled with CFSE before co-culture with immune effector cells. Following incubation, dead target cells are identified using viability dyes such as 7-AAD, allowing precise quantification of immune-mediated cytotoxicity at the single-cell level.

Best suited for

  • PBMC-mediated cytotoxicity
  • Mechanistic studies
  • Multiparametric immune profiling
  • Validation of immune cell function

Key Advantages

  • High specificity
  • Single-cell resolution
  • Simultaneous analysis of multiple cell populations
  • Compatible with complex immunophenotyping workflows

Figure 1: Flow cytometric detection of CFSE+/7-AAD+ target cells following immune-mediated killing.

Luciferase-Based Cytotoxicity Assays

Luciferase-based assays provide a rapid, highly sensitive and quantitative method for measuring immune-mediated target cell killing.

Target cells expressing firefly luciferase generate a luminescent signal proportional to cell viability. As immune effector cells eliminate target cells, luminescence decreases, providing a direct measure of cytotoxic activity.

These assays are widely used for evaluating CAR-T cells, CAR-NK cells, ADCC and T-cell engager therapeutics because they combine excellent sensitivity with high-throughput capability.

Best suited for

  • CAR-T development
  • CAR-NK potency assays
  • ADCC evaluation
  • High-throughput therapeutic screening

Key Advantages

  • Excellent sensitivity
  • Quantitative readout
  • Rapid workflow
  • Ideal for screening large sample numbers

Figure 2: ADCC-mediated killing of Firefly Luciferase NALM-6 cells induced by an anti-CD19 antibody.

LDH Release Cytotoxicity Assays

LDH release assays offer a straightforward, label-free method for quantifying cell death.

Lactate dehydrogenase (LDH) is a stable intracellular enzyme that is released into the culture supernatant when cells lose membrane integrity. The released LDH is quantified using a colorimetric reaction, providing an indirect but reliable measure of cytotoxicity.

Because no target cell labelling is required, LDH assays are well suited to routine screening workflows.

Best suited for

  • Routine cytotoxicity screening
  • Label-free detection
  • Standard laboratory workflows
  • Cost-effective testing

Key Advantages

  • Simple protocol
  • No fluorescent labelling
  • Compatible with standard plate readers
  • Scalable for larger studies

Figure 3: Dojindo's Cytotoxicity LDH Assay Kit-WST demonstrates higher sensitivity than comparable assays.

Typical Research Applications

Typical Research Application What you’re measuring Recommended Assay
CAR-T Cell Development Engineered T-cell killing potency Luciferase-Based / Flow Cytometry
CAR-NK Cell Development NK-mediated cytotoxic function Luciferase-Based / Flow Cytometry
PBMC-Mediated Cytotoxicity Mixed immune population killing Flow Cytometry
ADCC Antibody-driven immune killing Luciferase-Based / LDH Release
T-Cell Engager (BiTE) Evaluation Redirected T-cell killing Luciferase-Based

Why Researchers Use Immune Cell-Mediated Cytotoxicity Assays 

Immune-mediated cytotoxicity assays enable researchers to:

  • Directly measure immune effector cell killing against target cells
  • Quantify therapeutic potency across CAR-T, CAR-NK, BiTE and antibody candidates
  • Compare immune responses using robust, reproducible functional readouts
  • Select assay formats tailored to mechanistic investigations or high-throughput screening
  • Support assay development, optimisation and therapeutic candidate selection

Quick Takeaway

Choosing the right cytotoxicity assay starts with your research objective. 

  • Flow cytometry delivers detailed single-cell analysis for mechanistic studies
  • Luciferase-based assays provide highly sensitive and scalable measurements for therapeutic potency testing
  • LDH release assays offer a simple, label-free approach for routine cytotoxicity screening.

Selecting the most appropriate method improves data quality and accelerates immune therapy development.

Need More Than Assay Kits?

From assay development and optimisation to preclinical functional studies, our Contract Research Organisation (CRO) supports immunotherapy projects on demand. Whether you are developing CAR-T, CAR-NK, ADCC or T-cell engager therapies, our scientific experts can help design and execute tailored cytotoxicity studies that accelerate your research.