Cell growth determination kit
MTT assay based on mitochondrial activity
Cell proliferation has been shown to have multiple functions in development and pattern formation, including roles in growth, morphogenesis, and gene expression.
Methods commonly used for this purpose are hemocytometer counting, determination of protein content, wet or dry weight measurement, and determination of the optical density (OD). While hemocytometer counting and protein determination have the disadvantage of being time-consuming and tedious, the measurement of wet or even dry weight is not practical for very small culture volumes.
An alternative method is based on the transformation and colorimetric quantification of MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.The respiratory chain and other electron transport systems reduce MTT and other tetrazolium salts and thereby form non-watersoluble violet formazan crystals within the cell. The amount of these crystals can be determined spectrophotometrically and serves as an estimate for the number of mitochondria and hence the number of living cells in the sample. These features can be taken advantage of in cytotoxicity or cell proliferation assays, which are widely used in immunology, toxicology, and cellular biology.
Principle :
The principle of the MTT assay is based in mitochondrial activity. For viable cells, mitochondrial activity is constant and thereby an increase or decrease in the number of viable cells is linearly related to mitochondrial activity. The mitochondrial activity of the cells is reflected by the conversion of the tetrazolium salt MTT into formazan crystals, which can be solubilized for homogenous measurement. Thus any increase or decrease in viable cell number can be detected by measuring formazan concentration spectrophotometrically using a plate reader at 570 nm vs 690 nm.
Components of the kit : MTT solution + MTT solvent