Table 3.
Assays that distinguish membrane-disrupting cell death pathways
| Assay | Apoptosis | Pyroptosis | Necroptosis |
|---|---|---|---|
| Count viable surviving colonies | ↓ | ↓ | ↓ |
| Measure intracellular ATP | ↓ (late) | ↓ (early) | ↓ (early) |
| Observe cell morphology | Cell shrinkage, membrane blebbing | Membrane bubbles, cell flattening | Cell swelling, cell membrane rupture |
| Detect the activation of mediators | Effector caspase cleavage | Inflammatory caspase/GSDM cleavage | MLKL phosphorylation |
| Uptake of cell-impermeable small molecule dyes (SYTOX Green or propidium iodide) | Late | Early | Early |
| LDH release | Late | Yes | Yes |
| HMGB1 release | No | Yes | Yes |
| Annexin V staining | Positive | Positive | Positive |
| DNA ladder assay, TUNEL assay | ++ | +/− | +/− |
Abbreviations: GSDM, gasdermin; MLKL, mixed lineage kinase domain-like pseudokinase; TUNEL, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling.