Cell-death assays are crucial tools for drug discovery and development, providing insights into the mechanisms of programmed cell death and drug-induced cell death. By using these assays, researchers can assess the efficacy and safety of potential drug candidates, optimize drug dosages, and identify potential adverse effects.
There are several types of cell death, including apoptosis, necrosis, and autophagy. Discriminating between these different types of cell death is crucial for understanding their mechanisms and identifying potential therapeutic targets. Apoptosis is a programmed cell death pathway that is tightly regulated and involves caspase activation, while necrosis is an uncontrolled cell death pathway that is stimulated by external factors. Autophagy is a process of cellular recycling that can lead to cell death when its levels are excessive.
Understanding the type of cell death induced by a drug candidate is important for drug candidate profiling because different types of cell death have different mechanisms and implications for drug efficacy and safety.
The commonly used cell death assays are summarised in the table below:
| RealTime-Glo™ Annexin V | CaspGLOW™ | DeadEnd™ TUNEL | CYTO-ID® | |
| Working principle | Assay utilizes Annexin V-luciferase fusion protein that binds to phosphatidil serine exposed during early apoptosis. Additionally it detects membrane damage by DNA-binding fluorescent dye. | Assay utilizes specific caspase-3 inhibitor conjugated with FITC, which binds irreversibly allowing specific detection of apoptotic cells. | TUNEL detects DNA fragmentation by incorporation of fluorescein-12-dUTP at 3´-OH DNA ends by Terminal Deoxynucleotidyl Transferase. | Assay utilizes cationic amphiphilic tracer (CAT) that selectively enters pre-autophagosomes, autophagosomes, and autolysosomes. |
| What is detected | phosphatidyl serine exposure and membrane integrity | caspase-3 activation | DNA fragmentation | autophagic vacuoles |
| Signal type | luminescence + fluorescence | fluorescence | fluorescence | fluorescence |
| Platform | plate reader | plate reader / fluorescence microscopy / flow cytometry | fluorescence microscopy / flow cytometry | fluorescence microscopy / flow cytometry |
| Sensitivity | 4/4 | 4/4 | 3/4 | 3/4 |
| Throughput | high | high | high | medium |
| Is cell lysis required ? | no | no | no | no |
| End-point / real time | Real time | End-point | End-point | End-point |
| Multiplexing | yes | no | yes | yes |
| Model system | adherent and suspension cell cultures | |||
In addition to the above assays we also offer alternative approaches to suit specific experimental needs, see more info.
Example output:
