1. Determine the cytotoxicity of drugs (including other treatment methods, such as radiation irradiation) on in vitro culture;

2. Cell proliferation and cell activity determination.

The detection principle is that succinate dehydrogenase in mitochondria of living cells can reduce exogenous MTT to water-insoluble blue-purple crystal A and deposit it in cells, while dead cells have no such function. Dimethyl sulfoxide (DMSO) can dissolve methylene in cells, and its absorption value is measured at 490nm wavelength by enzyme-labeled instrument. In a certain range of cell numbers, the number of MTT crystals is directly proportional to the number of cells. Judging the number of living cells according to the measured absorbance value (OD value), the greater the OD value, the stronger the cell activity (if the drug toxicity is measured, it means that the drug toxicity is smaller). For the above biological knowledge, human miRNA/ human microRNA:/101595/