GRK5-IN-5

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.

Cardiac morphometry is based on quantitative histological and stereological assessment of myocardial structure, including cardiomyocyte size, number, and extracellular matrix composition, to evaluate cardiac growth and remodeling under physiological or pathological conditions. Design-based stereology is considered a reference framework for obtaining unbiased estimates of structural parameters such as cardiomyocyte number, volume, and tissue architecture, enabling quantitative comparison across experimental groups. Histological image-based morphometry further enables measurement of cardiomyocyte cross-sectional area and collagen deposition using microscopy combined with image analysis software, allowing assessment of hypertrophy and fibrosis in cardiac remodeling models. These morphometric readouts reflect underlying biological processes such as cardiomyocyte hypertrophy, loss, or structural reorganization during disease progression or experimental stress.

The following protocol uses the MTT colorimetric assay as a classic literature-established method for assessing cell viability/metabolic activity in cultured mammalian cells. MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] is reduced by metabolically active cells to a colored formazan product; the amount of formazan is quantified spectrophotometrically and provides an indirect measure of metabolically active viable cells. Importantly, MTT reduction reflects cellular oxidoreductase/metabolic activity rather than an absolute direct count of living cells, so changes in cellular metabolism can alter the signal independently of cell number.