SRI-22136

Cytotoxicity assays are usually based on the assessment of cell membrane damage, which can also be indirectly detected by measuring cell viability. Detection methods include MTT assay, CKK-8 assay, LDH assay and ATP assay, etc.

Hematoxylin-eosin staining is a routine histological method that stains nuclei mainly blue-purple with hemalum and stains cytoplasm, extracellular matrix, and many stromal components pink with eosin, allowing tissue architecture, cell morphology, necrosis, inflammation, fibrosis, tumor growth pattern, and treatment-associated injury to be evaluated by light microscopy. In cancer cells, primary neurons, mouse tumor models, intestinal organoids, inflammatory macrophage preparations, and drug-screening tissues, H&E is a morphology assay rather than a molecular assay; it should be interpreted with complementary molecular or immunostaining assays when the biological question concerns specific proteins, RNA levels, ferroptosis, mitophagy, or immune phenotypes.

Choosing the right model animal is a validity-driven decision in which the species, strain, sex, age, genetic background, disease-induction method, outcome measures, and welfare burden must match the scientific question rather than laboratory tradition or convenience. A model should be selected by judging face validity, construct validity, and predictive validity: whether it resembles the human phenotype, whether it reproduces relevant mechanisms, and whether results are likely to predict human biology or treatment response. Animal studies often fail to translate because of species differences, weak disease resemblance, poor experimental design, inadequate reporting, publication bias, and underuse of randomization, blinding, and sample-size justification. Unresolved questions include how to rank competing models objectively, how much human-disease complexity must be reproduced for a given objective, and when non-animal systems such as organoids, ex vivo tissue, or computational models